Installation and Operator s Manual. MPI-16/8 Series Capacitive Discharge Ignition Systems. MURPHY POWER IGNITION San Diego, CA.

Transcription

1 Installation and Operator s Manual MPI-16/8 Series Capacitive Discharge Ignition Systems MURPHY POWER IGNITION San Diego, CA. USA September,001

2 TABLE OF CONTENTS 1.0 System Description Technical Overview Controller Specifications Special Features Spark Plug Demand Voltage (KV) measurement Energy Control Primary and Secondary Diagnostics Compression Detection System applications Stroke engines Stroke engines Coil Selection Guidelines Crank Method Selection Guidelines MECHANICAL INSTALLATION REQUIREMENTS Controller...1. Sensors.... Coils ELECTRICAL INSTALLATION Controller Enclosure Grounding...8. Power Wiring and External Fusing Requirements Using Engine Starting Batteries for MPI Power...9. Internal Fuses...9 Location and rating...1. Sensor Wiring Sensor testing techniques....5 Coil Wiring and Primary Harness Field Wiring Diagrams for External Equipment Using the MPI to Power Annunciators Tachometer Connections Fuel Shutoff Valves Relay Output Connections Discrete Input Connections Using the /0 ma Input Secondary Modbus Port Specifications Keypad/Display Panel Functional Description 66.1 Introduction Programming Parameter Descriptions PRELIMINARY SYSTEM CHECKOUT Power Connections Panel and Firmware Verification Engine Data Verification Firing Order and KV Measurement Check Crankshaft and Camshaft Sensors and Alignment Check Dry Run Check Idle Test Run Testing Shutdown Devices...15

3 5.9 Full Load Test TROUBLESHOOTING GUIDE Error Messages Firmware Release History...18

4 THIS EQUIPMENT IS SUITABLE FOR USE IN CLASS I,DIV, GROUPS BCD OR NON- HAZARDOUS LOCATIONS ONLY WARNING-EXPLOSIVE HAZARD- SUBSTITUTION OF COMPONENTS MAY IMPAIR SUITABILITY FOR CLASS I, DIV WARNING- DEVIATION FROM THESE INSTRUCTIONS MAY RESULT IN IMPROPER ENGINE OPERATION WHICH COULD CAUSE ENGINE DAMAGE AND/OR PERSONAL INJURY. WARNING- THIS IGNITION SYSTEM MUST BE PROGRAMMED PRIOR TO USE ON AN ENGINE. REFER TO THE PROGRAMMING SECTION FOR COMPLETE INSTRUCTIONS. Note to Reader: Please feel free to notify Murphy Power Ignition of any errors or omissions. to: Fax to: Write to: MPI, 60 Riverdale St. San Diego Ca 910

5 1.0 System Description 1.1 Technical Overview The MPI 16/8 series ignition systems are capacitive discharge, low-tension type designs. The system is capable of generating precise spark timing that improves fuel economy, load balance and ignition stability. The controller design incorporates a state-of-the-art, 16-bit, microprocessor. This technology provides the user with a highly flexible solution to his ignition needs. Because of the microprocessor-based design, the user can select from one of five methods of crankshaft sensing. This degree of flexibility permits the user to take advantage of the best method for his specific application. A unique feature of this product is the new, patented, spark plug demand voltage measurement that is available through the use of any MPI coil. It allows the microprocessor to: 1. measure demand on each cylinders plug for diagnostic purposes. use the measured demand for automatic energy control. use the measured demand in the unique camless crank method to determine the compression stroke eliminating the need for a camshaft sensor. This new design includes a keypad/display that has its own microprocessor. It communicates with the controller s Signal Processing Module (SPM) using the industrial standard MODBUS RTU protocol. All programming functions are done through this keypad/display, no chips or PC or hand held computer is required to program it for an application or run special offline diagnostic tests. The units can be purchased with the keypad/display mounted in the door or purchased without a display in the door. The display can be purchased separately and mounted in a remote location. The communication link is a serial RS-85 port that can drive cables up to ¼ mile in length. The latest design incorporates a new shutdown interface that allows an external shutdown device to ground the U lead similar to how a magneto is controlled. Or, a more sophisticated approach can be used such as controlling the ignition enable signal from a PLC, or a newer annunciator. The system is modular in design. For engines of 8 cylinders or less, the user can select a lower cost MPI-8D model. The MPI-8D or thempi-8 (non-display unit) has all of the features of the MPI-16 series. The difference is the MPI-8 uses a single, 8-channel output module. The MPI ignition product line includes the following: 1. Four controller versions, MPI-16D,-16,8D,8. Five coil styles IT-0 non-haz open lead ITX-0FM (flange mount) CSA approved ITX-0RM (remote mount) CSA approved ITX-150-1/6 integrals (coil-on-plug) 1, 6 respectively, CSA approved. Primary Harnesses, Refer to drawings 00611, Sensors and related harnesses. 5. Trigger disks. 5

6 Figure 1.0 Products IT-0 ITX-0RM ITX-0FM MPI-16D Controller ITX-150-6/1 Sensors and trigger disks 6

7 Figure.0 Typical installation block diagram 7

8 1. Controller Specifications General: Ignition Type: Capacitive-Discharge Maximum Spark Energy: 15 mj Number of Cylinders: 8/16 -Stroke/-Stroke Supply Power: 1- VDC, amps avg. at maximum firing rate. Accuracy: 0.5 degrees Max RPM: 000 Operating Temp 0, +70 C Hazardous Rating: CSA Class 1, Div, Groups B,C,D T Temp Code Certificate # Communications: Serial Port #1 Primary: RS-85, Modbus RTU Slave protocols, 9600 Baud Used for MPI keypad/display panel Serial Port # Secondary: RS-85, Modbus RTU Slave protocol, 00, 800, 9600 baud rates available, data format 1,8,1 no parity Note: available in th qtr 001 Used for communicating with a customer furnished Modbus Master Device. Supports multi-word writes, multi- read functions. This port provides for a remote located user to observe the systems operation. A limited number of parameters are made available for writing to over this port. This port provides for concurrent operation of the Operator Pages during normal run operations. No off-line diagnostics or programming functions is supported over this port, those are only available over the primary port. Inputs: PIP (Position Input Pulse): Function: provide incremental crankshaft pulses. Any quantity in the range of 0-60 per revolution can be used. Signal source: ring gear teeth, drilled holes in the flywheel or crank or camshaft mounted trigger disk Sensor type: passive mag pick-up or active hall-effect sensor, min input.5 volts peak Electrical Interface: 7 K ohm input impedance, 1/REV (Once Per Revolution): Function: provide a reference pulse for the start of a new engine cycle and is also used for RPM measurement. 1 pulse located at TDC#1, +,- 15 degrees. Signal source: hole, ferrous target, trigger disk Sensor type: passive mag pick-up, or active hall-effect sensor, min input.5 volts peak Electrical Interface: 7 K Ohm input impedance CAMREF (Cam Reference): Function: 1 pulse at TDC#1 compression is required for cycle distinction for -stroke applications where a non-camless method is desired or if non-mpi coils are in use. This pulse must act as a window for the 1/REV pulse on the compression stroke. Caution: The polarity of this pulse is user programmable, for the MPI dual halleffect the polarity selected should be negative. For other sensors the user must know the polarity and match the programmed polarity to it. Signal Source: magnet target, can be north or south pole, user must know for correct wiring of the MPI dual hall-effect sensor. Sensor type: MPI Dual Hall-effect 8

9 Electrical Interface: Internally pulled up to 10 volts. Sinks 5 ma. IGN Enable (Ignition Enable): Function: Control over ignition, closed contacts disables ignition, shuts down Tank capacitor charging circuits. Signal Source: external switch or relay or PLC open-collector or open-drain. Sensor Type: manual switch, relay contacts or PLC discrete output Electrical Interface: Opto-Isolated, internally pulled up to +15 volts. Sinks 5 ma. Use an external dry contact (do not apply an external voltage) A/B Select: Function: selects the timing schedule, open contact for schedule A, closed for B This input also selects which /0mA input is active. Signal Source: external switch or relay or PLC open-collector or open-drain. Sensor Type: manual switch, relay contacts or PLC discrete output Electrical Interface: Opto-Isolated, internally pulled up to +15 volts. Sinks 5 ma. Use external dry contact only (do not apply an external voltage) Alarm Acknowledge: Function: This input is used to clear the alarm que. Signal Source: external switch or relay or PLC open-collector or open-drain. Sensor Type: manual switch, relay contacts or PLC discrete output Electrical Interface: Opto-Isolated, internally pulled up to +15 volts. Sinks 5 ma. Use external dry contact only (do not apply an external voltage) /0 Milliampere A&B Function: Each of these provides for controlling the ignition timing (retard only) from an external device. Signal Source: Many options here, these inputs can be driven by different sources. Any compatible temperature transducer could be used to protect against detonation. A device that sensor fuel quality could be used. A PLC with a /0 ma output channel could be used. Another aspect of the flexibility is that any transducer can be monitored without affecting timing. The display can be scaled to read out in useful units. Check with your distributor on how to scale these inputs to show appropriate engineering units. For example, if a temperature transducer is connected, the reading shown on the display can be scaled from the -0 ma to a temperature in degrees F or C. Sensor Type: Analog transducer externally powered. Electrical Interface: The MPI inputs have a 50 ohm dc termination across the +,- terminals. This input must be externally sourced. Note: these inputs cannot be wired in series, each input must be driven by a dedicated sensor. The U Lead : Function: This lead provides power to run ignition powered devices. It can also be grounded to shutdown ignition. This lead is connected to the tank capacitor through a 0K ohm resistor on the output module. Only Ouput Module #1 is used. The connection from the Output Module to the USER IO board is made at the time of assembly, no extra wiring is required. Signal Source: Any device that applies a ground can be used. Sensor type: Annunciators, overspeed devices etc. Electrical Interface: This input is pulled up to the volts supply through a k resistor and an opto-isolator diode on the USER I/O board. The ignition-powered devices will have this interface voltage applied to it whenever the tank capacitor drops below volts. During operation the tank pulses will not decrease all the way to zero volts when it is fired. It will only drop down to volts. This may be a problem for some equipment such as tachs and other speed monitoring devices. 9

10 Check the spec on these devices to be sure they re compatible. They may need to see the voltage drop down closer to ground before it can recognize the pulse. The V lead: Function: This is the common sense lead that comes in from each coil. The signal that is carried into the unit on this lead is used to determine the demand voltage on the plug. Signal Source: Any MPI coil Sensor Type : Any MPI coil Electrical Interface: The V lead is internally jumpered from the V pin on J1 (primary connector) to the sense lead input on the SPM. The user only needs to make the sense lead connections from the coils to the primary harness. Volt Supply: Function: This is the main supply connection to the unit. This input supplies power to the tank capacitor charging circuitry, the low voltage level for the digital logic is derived, and the 15volt supply for any active sensors is derived from this input. This input also supplies power to the keypad/display unit. The circuit design has taken in account the need to keep current peaks at a minimum. They are a source of noise to other equipment sharing the same supply and higher currents result in higher voltage drops which could create problems as well. The MPI has significant internal storage capacity. High current peaks during the tank capacitor charging cycle are taken from the local storage devices. The microprocessor controls an electronic switch so that it can isolate this input from the charging supplies while maintaining power in all other areas. The microprocessor isolates this input from the charging circuits during the firing cycle as well as the charging cycle. After the tank capacitors have fired out to the coil and then has been fully re-charged, the microprocessor connects this input to the internal storage capacitors for recharging at a much slower rate therefore reducing the peak current demands from the volts supply. Although 16 awg is recommended, the system will function perfectly well through 18 awg wire. Caution: The volt supply is distributed throughout the unit through fuses to each major internal assembly. But, if the + lead is inadvertently connected to the RTN (ground) terminal instead of the VDC Input terminal, a high current flow could result and damage can occur. All of the connections with RTN as part of the name are internally connected together. If any of these RTN connections are wired they could provide a redundant path back to the supply -, effectively grounding the unit. Therefore, it is recommended to install a fuse in the + line between the supply and controller to provide a means of protection if this ever happens. Please refer to the electrical installation drawings for details. Outputs: Coil Drivers: Pins A,B,C,D,E,F,G,H,J,K,L,M,N,P,R,S Electrical Characteristics: These outputs conductors are connected to the tank capacitor through an electronic switch. This product uses a power device widely accepted in all fields where electronic switching of high current is required. The technology is called Insulated- Gate-Bipolar-Technology or IGBT. This technology is a combination of FET and Bi-Polar processes. The FET provides the ability to turn the device on and off by an 10

11 application of appropriate voltage on the Gate and Emitter. The Bi-polar section handles the high current flows with the advantage that bi-polar solid state physics offers over a FET output circuit semiconductor. It s the best of both worlds combined in to a single device. The IGBT and associated circuits provide a high-side output interface. This means that the positive side of the coil is sourced by the IGBT when its time to fire. There is no common rail voltage that is constantly applied to the + side of the primary. These outputs can withstand shorts to ground indefinitely without suffering any damage. They can be shorted to each other without damage. They can be left open circuited indefinitely without resulting in any damage. When a primary lead is open the voltage on the lead will float up to the tank voltage but its through a 50 K Ohm resistor therefore little energy can be delivered. The low DC resistance of the primary winding provides a current path for the IGBT bias circuits which is why the tank voltage appears on this lead if it is open. Lastly the IGBT cannot be turned on while the primary lead is open. The T Lead: Each Coil (-) connection must be connected back to the output module via the T lead in order for the tank capacitor, IGBT and coil to have a complete circuit when the IGBT closes. The T lead goes back to the (-) side of the tank and it must be common to all coil (-) terminals. The T lead must be connected to the ground terminal of the ignition powered device or to a common ground shared by the device and the T lead. The skid frame can work, the engine block can be used, but the best method to be certain a reference is made to the T lead is to run a small gauge wire from the device ground terminal back to the T lead. The T lead must be the heavy gauge from the coils, awg. The most reliable method it to run all of the coil (-) leads into a junction box and all of them jumpered together. Then connect the T lead to this common node and it s done. The U Lead: This lead has been defined in the input circuit specifications with an emphasis placed on the shutdown circuit. As an output, it is the supply voltage for ignition powered devices. This lead is connected internally to a 0 K, watt resistor and the other end of the resistors connects to the tank capacitor. The purpose of the 0 K resistor is to limit the current drain so the charging circuits are not constantly working and creating excess internal heat. The other purpose it to protect the charging circuits from a direct short to ground if the device being powered is designed to ground the IGN input as in the case of many Murphy annunciators. The user must calculate the total load current from the devices being powered and compute the resultant voltage drop (IR drop) across the 0 K resistor. The available voltage at the device for the applied load will be the tank voltage less the voltage drop across the resistor. ISO_CAM, ISO_PIP, ISO_1/REV: These are opto-isolated outputs of the indicated signal. These are -terminal, collector/emitter connections. They are intended for use by other equipment and provide an isolated barrier between these outputs and the signal used by the MPI controller. These outputs can be shorted together without affecting the MPI operation. The maximum load current is 5 ma. The maximum pull up voltage is 60 VDC Relay Contacts: For the Ignition On,Alarm, and Shutdown relays Form C configuration Maximum closed contact current: 1.0 Amps Maximum open contact voltage: 0 VDC 11

12 1. Special Features The MPI controller has been designed with several features that were made possible by the new smart coil technology and the capabilities of the system s microprocessor. These features are discussed in the following pages to help the user better understand what these features can do for him. Having a better understanding will lead to quicker diagnosis of problems and shorter down time. The features that are considered as part of newly developed technology are: 1. Spark Plug Demand Voltage (KV) Measurement. Energy Control. Compression Detection 1..1 Spark Plug Demand Voltage Measurement The term spark plug demand voltage is known by several different names, but they all mean the same thing. Some of the other identities are: 1. secondary voltage. breakdown voltage. KV measurement These all refer to that condition when the voltage impressed across the plug gap is high enough to cause current to flow across the gap in the form of an arc. Once the arc starts the voltage across the gap is reduced to approximately < 1000 volts or 1Kilo Volt (KV). The breakdown voltage alone does not guarantee combustion, other important factors are the total electrical energy of the arc, the duration of the arc and the air/fuel ratio within the gap. But if the breakdown does not occur there will be no normal combustion. This is why the breakdown voltage is such an important piece of information. It is a leading indicator for diagnosing combustion related problems and provides prognostic indications as well. There are many factors that can affect how high the voltage much reach before an arc can occur. Here are some of the major factors: 1. Plug gap distance, longer distance requires more voltage.. Dielectric properties of the atmosphere between the gap, air/fuel ratio.. Cylinder pressure at the precise angle when the voltage is building up. [It could be argued that factors 1& contribute to the dielectric properties but they are delineated for better understanding.] The primary benefit derived from knowing the breakdown voltage is being able to predict the end of the plug life. The user can see very precisely when the demand voltage is approaching the maximum KV available. Knowing this information may allow the user to run longer between plug changes than before when the plugs were changed based on a time-table that ensured large margin of safety. Since each plug s demand voltage is measured and displayed, the system provides individual cylinder diagnostics. The measurement of the demand voltage is accomplished by using the signal provided by the coil sense lead. The sense signal shape replicates the actual voltage waveform applied to the plug. The microprocessor uses a transfer function of the coil circuit. A transfer function is a mathematical equation (model) that relates all of the variables that determines the spark plug voltage waveform up to the instant of breakdown. These variables include: 1. coil turns ratio. coil primary and secondary inductance. coil primary and secondary resistance. tank capacitance 5. initial charge of tank voltage 6. IGBT turn-on to breakdown time 1

13 Of these factors the first four are constants. The fifth is the initial charge of tank voltage, which is known. And lastly, the sense lead and associated circuitry provides the direct measurement from the secondary side of the coil of how long it took for the voltage to reach the breakdown point from the instant the IGBT was turned on. With all of these factors applied to the transfer function s algorithm the resultant calculated output based on these measure and fixed factors is the actual KV amplitude at the precise moment of breakdown. 1.. Energy Control: The energy control feature provides a means of automatically reducing the energy applied to the plug but not to the point where reliable breakdown is sacrificed. The objective is to reduce the erosion rate of the plug s high voltage and ground electrodes caused by the electrical current flowing during the arcing period. The demand voltage plays a crucial part in this scheme since it provides a measurement of the minimum required voltage. The Automatic Control algorithm can reduce the maximum available voltage and still provide some headroom for reliable combustion. The tank voltage and stored energy are related by the following relationship: E (energy in joules) = ½ Tank Capacitance x Voltage It can be seen that by controlling the tank charge in volts the energy can be controlled as well. Changing the tank capacitance would mean a change in the component, which is not a practical thing to do. By reducing the voltage, the maximum output voltage on the secondary is directly influenced. The relationship between the peak secondary voltage and the tank voltage is: Vmaxsec(KV) = Vtank x coil turns ratio. The coil turns ratio is the ratio of the actual times the secondary wire has been wrapped around the core of the coil to the actual number of time the primary wire has been wrapped around on the core. This is a fixed number. The relationship shows a direct relationship between the primary voltage and the secondary voltage. It s important to remember this relationship is useful for calculating the maximum possible secondary voltage if no breakdown occurs. The energy control algorithm calculates the maximum secondary voltage that can be theoretically generated and calls it the Maximum Available KV. The actual measured voltages from each plug are made and the highest one is picked out for the control feedback. This is referred to as the Max Measured KV. Both of these variables can be seen on the display as the control loop (algorithm) works. As the control reduces the Max Available it compares it to the Max Measured. When they are within a safe margin the control loop holds the Max Available constant. As the Max Measured (demand) increases over time, the Max Available will be raised to maintain the margin to ensure reliable combustion. 1.. Primary and Secondary Diagnostics: The ability to measure the secondary demand voltage significantly enhances the system s diagnostic capabilities. The system also monitors the tank voltage at specific times to determine the tank discharge rate. The rate of tank discharge is a leading indicator of certain conditions that can be diagnosed and dealt with. The combination of these secondary and primary measurements provides a very useful diagnostic tool The system diagnoses every plug for every firing for one of 5 conditions. 1. Normal operation: this is the condition where the plug is reading within the expected KV range. The controller measures the secondary breakdown voltage and also checks for a normal tank discharge rate.. Open Primary: The secondary demand voltage indicates no arc on the plug and the tank capacitor has not discharged. 1

14 . Shorted Primary: The secondary demand voltage indicates no arc on the plug and the tank discharge rate was almost instantaneous.. Open Secondary Lead: The secondary demand indicated no arc on the plug and the tank discharge rate was excessively long. 5. <5 KV: This could be a normal condition, but the secondary indication was so low that it was unable to discern any arc. The tank discharge rate shows a faster than normal discharge rate. If the plugs are test fired in atmosphere the dielectric strength of air is low and a very low demand is placed on the secondary output. An arc would occur but it would be at a very low demand, <5KV. For an engine running at idle with low cylinder pressure and an air fuel mixture in the gap the demand would also be low. Fuel reduces the dielectric strength. Under load the additional cylinder pressure increases the dielectric strength more significantly than the fuel need to maintain the load so the overall dielectric strength increases and requires a higher breakdown voltage. 1.. Compression Detection: The secondary demand is significantly affected by pressure built up in the cylinder. Therefore, if the system uses the coil to arc the plug under different pressure conditions the measured demand would reflect at least the relative difference in these conditions. For -stroke cycle engines the piston makes trips up through the cylinder before it repeats the process. One time coming up to the top, the valves in the head are closed and the piston compresses the air/fuel charge in the cylinder. The next time it comes up the exhaust valve is open to allow the piston to literally shove the burnt gases out of the cylinder preparing it for the subsequent ingestion of a fresh air/fuel charge. Since the ignition arc needs to occur on the compression stroke the system must be able to determine when the compression stroke is occurring. If there was a way to initially indicate to the system which stroke was which during initial cranking cycles, it could keep track of the subsequent cycles simply by using the PIP and 1/REV sensors on the crankshaft. These two sensors provide indications of the completion of crankshaft revolutions but they cannot provide the system with an initial indication of the compression stroke. This system, through the secondary demand measurement can accomplish this. The algorithm for initially synchronizing to the compression stroke is accomplished by a special test fire mode during cranking. During this test firing mode, while the engine is cranking, the system fires cylinders #-n, where n is half of the cylinders. The sequence starts with cylinder # in the firing order and it continues to fire through the order on successive revolutions. For example, if it s an 8-cylinder engine with a firing order of 1,8,,,5,6,7, the system will fire cylinders 8,, &5 for four consecutive revolutions. This provides the system with readings during compression and exhaust strokes for each of these cylinders. The system uses the crankshaft sensors to provide the accurate timing pulses necessary to fire half of these cylinders at the same crank angle. This means the plug is fired when the piston is in the same relative position coming up to the top of the cylinder on each stroke. We know that on one trip up the pressure will be significantly higher than the other at the same position in the cylinder. So will the demand voltage. The measurements of the demand voltage are stored and processed to determine the cycle pattern. After revolutions for half of the engine s cylinders the high-demand, low-demand pattern is easily seen. The result is the system knows what the cycle, compression or exhaust, will occur on the 5 th and subsequent cycles. The cylinder s pressure affect on the plug demand voltage provides a true indication of the stroke. Even a camshaft sensor has to be aligned mechanically, it cannot tell the system that the engine is on compression. The system has to assume that the user has aligned it to the compression stroke and the signal polarity is correct for the compression stroke. 1

15 1. System Applications This section is dedicated to providing guidelines regarding system level decisions. The information presented is intended to help assure that all of the major design decisions have been addressed. CAUTION NOTE: All systems should provide a means of holding off the fuel during start up until the ignition controller has indicated it is firing. The controller has a relay called IGN_ON that is intended to support this function. A pure time delay for the fuel valve is NOT the best approach since this would assume the ignition would come on. The best approach is to use the IGN_ON relay to control shut-off valves directly (if it draws less than 1.0 amps) or to indicate to a fuel control system when it can apply fuel to the engine Four-Stroke Engines This ignition system is ideally suited for -stroke engines in the horsepower range of bhp, -16 cylinder engines. The features this system contains have been specified based on needs encountered by this engine group. Applying this system to an engine of less than 500bhp may not be the best economic approach since smaller engines typically use fewer features and have fewer number of cylinders than their larger counterparts. Many of the smaller engines can also be found to operate well over the upper RPM limit of 000 rpm. 1.. Two-Stroke Engines This system can be used on many -stroke slow-speed engines. These engines typically run in the rpm range of rpm. This system can accommodate this speed. Consideration needs to be given to the use of this system in that this system can only fire up to 16 outputs and no two outputs can be fired simultaneously. Since most slow-speed engines have large bores, there are typically spark plugs per cylinder in order to increase the burn rate of such a large volume of fuel-air charges. The MPI ignition system can fire coils wired in parallel. A maximum energy level of 15 mj is divided between the two coils. This energy level is typical of systems that are specifically designed for large-bore, slow-speed engines. The new feature in the MPI system that provides for spark plug demand voltage measurement is also available for dual coil, however the sense leads must be separated into two common nodes. Say for example there are two coils per cylinder, a left side and right side coil per cylinder. All of the left side coils would have their respective sense leads chained together and go to a select switch. All of the right side coils would do the same. The common of the select switch would be wired into the system. Then the user would position the select switch to read the KV levels from either the left or right set of coils. The diagnostic checks are still functional with dual coils. For engines that have cylinders simultaneously firing, which means four coils firing at once, the user needs a -position selector switch for the sense lead. The tank capacitors need to be put in parallel in order to maintain adequate energy to each coil. The user should consult the distributor for this type of application. Another solution to this application is to use two MPI controllers, each one dedicated to firing one of the two simultaneously fired cylinders. This would also require, -position selector switches for the sense lead. 1.. Coil Selection Guidelines MPI offers 5 different coil styles. They are divided into two basic categories, 0 volt, and 150 volt. These are the nominal primary firing voltages. There are different coil styles of the 0 volt and styles for the 150 volt coils. Listed below are the 5 different coils and their intended application: 1. IT-0 : This coil is intended for non-hazardous applications. It is also the least expensive coil. It provides duration of usec and draws a current pulse of 7-10 amps peak. The G stud is the critical ground for the secondary 15

16 circuit. A jumper is made from the G terminal to the mounting bracket. These coils are intended to be mounted directly onto the head so that the coil bracket makes electrical ground connection to the head.. ITX-0FM: This is a CSA rated coil for Class 1, Div locations. It has a nickel plated -bolt flange for mounting to the valve cover. It has the same electrical performance as the basic IT-0 coil. This coil is useable on engines such as the lean-burn 516 Cat engine.. ITX-0RM: This is another CSA rated coil for Class 1, Div locations. It is the Remote Mount version of the basic coil. It is completely encased in a metal housing. The mounting flanges provide the electrical ground for the secondary and therefore should be mounted directly onto the head or if mounted off the head, the cases should have a grounding wire brought from the mounting bracket to the cylinder head for a short loop for the spark plug current. This coil accommodates a shielded primary harness and a shielded secondary harness. This coil has the same electrical performance characteristics as the basic IT-0 coil, therefore the spark duration is usec.. ITX-150-6: This is another CSA rated coil for Class 1, Div locations. The -6 refers to its overall length of 6 inches. This coil has the benefit of threading directly onto the shielded spark plug, which eliminates the need for a high-tension lead and its associated cost. However, due to its small diameter it is impossible to have many turns of wire wrapping around the core. This creates a very low inductance, almost a short circuit, and the spark duration is very short. The duration is in the neighborhood of usec. This short duration is too short for some applications. Due to the in-cylinder mixing of fuel and air the ignition reliability for such short duration must be carefully analyzed. This short duration reduces the statistical probability of having fuel in the plug gap while the arcing is occurring. Engines that have induction systems that are designed to provide a higher concentration of fuel near the plug will work better with these coils than engines that try to achieve a more homogeneous mixture. Selecting these coils based on price alone will not guarantee reliable ignition will occur. Another penalty the user pays with these coils is the higher current peaks they draw. These coils will pull up to 0 amp peaks through the primary winding. This high current peak puts more stress on all of the components in the primary circuit path. Also, more noise is generated with these coils due to the high current spikes. Another drawback to these coils is the harsher environment they must operate in. Being directly mounted to the plug there is much more heat conducted to the coil that reduces reliability and longevity. The higher heat contributes to higher corrosion rates as well. In humid environs, moisture tends to build up in and around the coil when the engine is shutdown for any length of time because the coil does not breath well mounted down in the plug well. This also contributes to the higher corrosion rates. The poor breathing location also adds to the thermal issues. 5. ITX-150-1: This is the same coil as the ITX except it is 1 inches in length. All of the benefits and drawbacks of the 6 coil apply to this coil as well. 16

17 1.. Crank Method Selection Guidelines Crank method is the term used to define how the signals that are needed for timing and position reference are generated. The system provides for a selection of 5 different ways (methods) to install the sensors for providing these signals. The user can choose one that best suites his needs. What is described here is what each method entails and the pros and cons of each one. The basic signals that are needed by the system are briefly defined. 1. PIP signal: This is the incremental pulse that provides for tracking the crankshaft in between the 1/REV (top-dead-center) pulse. The PIP provides the angular position change information that allows the system to measure the movement of the crankshaft. These pulses are not directly related to the firing points. The controller compares the programmed timing angles to the measured position and when these two match a trigger pulse is generated for the appropriate cylinder.. 1/REV signal: This is the once-per-revolution pulse, obviously it occurs once per revolution of the crankshaft and is normally set up to occur at TDC #1 cylinder. There is a correction or calibration factor that the user can set into the system that allows for this pulse to occur within +,- 15 degrees of true TDC. This calibration is typically needed for very small adjustments but is does allow the user to very precisely match the digitally displayed timing to the indication seen with a timing strobe light.. CAMREF signal: This signal indicates when the 1/REV signal has occurred on the compression stroke. This signal is not needed for -stroke applications. A sensor on the camshaft normally generates the signal. For the two No-Cam methods this sensor is not required, the CAMREF signal is generated by the controller firmware. This is described in more detail below. It is very important to make sure the actual signal polarity on the compression stroke is the same as the polarity programmed in the controller. The controller allows for either positive or negative active signals in order to accommodate not only MPI hall-effect sensors (which ALWAYS output active negative signals) but other mfr s sensors as well. If the polarity of the signal on compression is opposite to the programmed polarity, the matching polarities will occur on the exhaust stroke and therefore the system will be firing 60 degrees out of phase. The following describes these methods, the order has no significance. 1. Ring Gear ( or drilled holes in the flywheel) For this method the PIP signal is generated by a -pin magnetic pick-up mounted so that it senses the ring gear teeth. The user programs the number of teeth per revolution into the controller. The range of teeth is 0-60 regardless of the timing pattern. The signal minimum amplitude is.5 volts. The 1/REV signal is usually a -pin magnetic pick-up also. For most applications a hole is drilled or stud of ferrous material is installed to generate the pulse. The hole or stud can be ¼ dia. x ¼ dp(or protruding). This is assuming the user installs the MPI -pin pick-up. The minimum signal amplitude is.5 volts. Mounting a magnet pin on the camshaft so that a hall-effect sensor can be used usually generates the CAMREF signal. The signal needs to be aligned so that it is active when the 1/REV occurs on the #1 tdc compression. The CAMREF signal polarity is critical and must match the signal when cylinder #1 is on compression. If the programmed polarity is mismatched, the controller has no way to know this set up is wrong and it will use the programmed polarity as the compression stroke. Therefore the ignition will be fired 60 degrees out of phase. Pros: This method is one of the easiest to set up and it provides very accurate, stable timing. Cons: The magnetic pick-ups mounted in the bell housing can become covered with grease and debris over time. This requires periodic cleaning and checking. This method requires a 17

18 camshaft sensor to generate the CAMREF signal thus increasing cost and complexity. The come-in speed is critical since the signal strength is directly related to the speed of the passing teeth. For some engines the speed can be difficult to reach due to a weak starting system. This requires the sensor gap to be reduced, which increases the potential for extra pulses once operating speeds are reached. The user must find the best gap that allows reliable starting without excess sensitivity that could cause unwanted pick up of flywheel anomalies. For large bore -stroke engines this method is often used with the exception that the ring gear teeth are NOT used but holes are drilled instead. Typically, the large bore engine flywheel teeth are chipped and worn to the extent the magnetic pick-up has difficulty reading them. Drilling 0 holes for the PIP and one hole for 1/REV is a reasonable method for the large bore -strokes. To date this method is rarely used since we have the compression detection scheme that eliminates the external CAMREF signal and its sensor. If coils other than MPI are used then this method is often used.. Crank Disk This method consists of mounting an MPI trigger disk on the end of the crankshaft. The disk has embedded magnets that provide the PIP signal and one magnet of opposite polarity that generates the 1/REV signal. The MPI dual hall-effect sensor is used for sensing the magnets. The CAMREF signal is generated by installing a magnet on the camshaft and mounting a second MPI hall-effect sensor to produce the CAMREF signal. The polarity of the CAMREF signal is critical and must match the programmed polarity on the compression stroke. IF the programmed polarity is mismatched the controller will fire the engine 60 degrees out of phase. Pros: This method allows the sensor for the PIP and 1/REV to mount outside the bell housing in a more benign environment. Timing accuracy is excellent. Another plus is the come-in speed is very low. This is a popular method for large bore -stroke engines. Cons: The disk requires the user to fabricate a mounting hub for the disk and brackets for the pick-up. This adds material and labor to the overall installation cost. The use of the CAMREF sensor is also an additional cost if the MPI coils and the compression detection scheme are not selected.. CAM Disk This method employs a single triggering disk that mounts on the engine s camshaft. The disk provides the PIP and 1/REV signals. Since this disk is mounted on the camshaft the 1/REV signal is always generated on tdc#1 compression. The firmware in this case knows to not expect a 1/REV on every crankshaft revolution. There are many disks available that can mount to the camshaft directly without needing additional hubs or brackets. Pros: This method is simple and easy to install. Since magnets are used the system come-in speed is very low. Cons: The timing accuracy and stability is limited by the mechanical condition of the cam drive mechanism. Also the disk is an additional cost item. The overall system cost is comparable to the ring gear method since it requires only a single sensor. The disk offsets the cost of the mag pick-ups.. No-Cam Ring Gear This method is one of two that uses the compression detection scheme that measures the spark plug demand voltage and determines compression by comparing readings over several successive firings. The details of this were described in a preceding section. In brief, the controller fires half of the engine s cylinders for four successive revolutions as soon as it has detected a good PIP count from the PIP and 1/REV signals. This usually occurs after 1- revolutions after the started has engaged. At the end of the th revolution of test firings the controller can determine what the stroke will be for cylinder #1 is on for the 5 th rev. On the 18

19 5 th rev the controller starts firing cylinders on every other rev and on the correct stroke. The firmware generates an internal CAMREF signal using the 1/REV and PIP signals after the correct stroke cycle is determined from the test-firing phase. The internally generated CAMREF signal occurs every 70 degrees in sync with #1 TDC compression. The PIP signal for this method is generated in the same way as the regular ring gear method. Gear teeth or evenly spaced holes can be used. The 1/REV signal is also generated the same way as in the ring gear method, a hole or ferrous stud post is located to pass under the 1/REV sensor at tdc#1. Pros: This method eliminates the need for a camshaft sensor and the associated effort to install and align. Using this method also relieves the user to ensure the CAMREF signal polarity is correct because there is no CAMREF sensor and polarity to worry about. This is a very popular method. It also eliminates the cost of the camshaft sensor. Cons: As with the ring gear method that has sensors in the bell housing, they are subjected to contaminants and oils that can render the pick-up inoperative. 5. No-Cam Crank Disk This method is similar to the Crank Disk method but this method does not require a camshaft sensor. The compression is detected as described above. The user mounts an MPI trigger disk to the crankshaft and uses the MPI dual hall-effect sensor for the PIP and 1/REV signals. Pros: no camshaft sensor, no alignment issues, cleaner environment for the PIP and 1/REV sensor. Cons: Requires user to mount a trigger disk to the crankshaft, and fabricate a bracket to mount the dual hall-effect sensor. This method has not been used much but it is becoming a popular method because of the higher reliability of the single sensor mounted outside of the bell housing. 19

20 .0 Mechanical Installation.1 Controller Mounting Considerations The controller has four shock mounts for vibration isolation. The unit should be mounted so that the front panel is vertical. The front panel should not be exposed to direct sunlight, as it will fade the panel over time. Also avoid locating the unit in close proximity to exposed exhaust manifolds or locations where the temperature can exceed 65 C. Figure.0 Controller Mechanical Envelop Modifications made to the enclosure are not recommended. We often see metal shavings from drilling holes in the enclosure scattered across the electronic circuit boards causing shorts and failures. Any units received for repair with mechanical modifications will be automatically treated as out of warranty 0

21 . Sensors..1 Sensor criteria for the Ring Gear, Crank Disk, No-Cam RG and No-Cam CD methods. When either the Ring gear or No-Cam RG method is used, the -pin mag pick-up, MPI p/n 000 should be used for both PIP and 1/REV. The 1/REV could use one output of the MPI dual hall-effect sensor 0001 or 0011 if the user mounts a magnet on the crankshaft. However; in most applications the user will put mag pick-ups on the flywheel, one on the gear teeth for the PIP signal and one on a drilled hole for the tdc reference signal 1/REV. Figure.0 is the specification control drawing for MPI s -pin, mag pick-up sensor. GEAR.5 A B NOTE.1.00 PIN A: Signal + PIN B: Signal - MPI-000 5/8-18UNF MS106A-10SL-P or Equiv Specifications: 1. Resistance: 0 +,- 0% 75 F. Inductance: 10 mh. Output Voltage:.0 volts Pk-Pk gap, 100 IPS, 8k Load. Temp Range: -65, +5 degrees F. REV DATE REV DESCRIPTION REL BY TITLE /05/00 PRODUCTION RELEASE SHN /0/00 PRE-PRODUCTION RELEASE JDN DWG. NO. ORIG DATE 10/09/01 SIZE LEGAL PIN SENSOR (MPI 000) DRN BY JDN SCALE NONE 000 PAGE NUM. TOTAL PAGES 1 1 MURPHY POWER IGNITION 60 RIVERDALE ST. SAN DIEGO, CA 910 Figure.0 -pin Magnetic Pick-Up sensor. This passive i.e. non-powered sensor is normally used for sensing holes, gear teeth, or ferrous studs or pins. The signals this sensor is normally used for are the PIP and 1/REV. The 1/REV hole in the flywheel for the 1/REV signal needs to be ¼ in dia min x ¼ deep min. A larger or deeper hole can be used up to the size of the sensor housing dia of 5/8 in. A hole too large would produce two pulses one at the leading edge of the hole and one at the trailing edge. If the hole is larger than 5/8 the sensor has time to null out during the interval the hole is moving under the sensor and then it will generate the second pulse when the trailing edge of the hole passes under it. Programming the polarity for signals that use passive mag pick-ups is not a critical item. The default polarities for the PIP and 1/REV signals are set to POSITIVE and this does not need to be changed unless the MPI active dual hall-effect sensor is used as it is for other crank methods. Setting the passive, mag pick-up sensor gap: For a hole in the flywheel the sensor should be turned in until it is stopped by the surface, then back it out from ¼ to 1 full turn and lock it down by tightening the jam nut. For a ferrous target that protrudes from the surface, the sensor should be turned in until it touches the top of the target piece then back it out ¼ to 1 turn and locked down. If the sensors are set for a 1 turn gap and the system does not read a good PIP count, the gap should be reduced. Some 1

22 engines crank slowly and there isn t enough target speed at the wider gaps to generate the minimum signal amplitude (.5 volts) to be detected. Some engines have a small amount of run-out so that the gap may widen during operation and prevent sufficient signal strength from forming. In general, its best to start wide, 1 turn, and go shorter if needed. To start off with a very short gap (1/ turn) risks contact from the flywheel or picking up unwanted signals from scratches or other marks on the flywheel. When a CAMREF sensor is required as it is with the Ring gear and Crank Disk methods, we recommend the use of the MPI Dual Hall-Effect sensor, MPI p/n 0001 rev A (1.8 reach) or the MPI p/n 0011 (6 reach). The default polarity for the CAMREF signal is set to NEGATIVE since the MPI dual hall-effect sensor is the usual choice. This active i.e. powered sensor requires a magnetic target for triggering. This sensor has both a north pole and a south pole output signal. Refer to Figure 5.0 (dwg 0001) for details. The target magnet can be the MPI p/n 0005, which is has the south pole facing outward therefore pin- should be used as the CAMREF signal. If an MPI trigger disk is used with a single magnet imbedded in the circumference, it will have the north pole field facing outward. Therefore pin- should be used when the target is the disk with a single magnet embedded in it. The output signal polarities from the MPI 0001 and 0011 sensors are always active low, i.e. negative going. The programmed polarity for any signal (PIP, 1/REV or CAMREF) using this sensor, should always be programmed for NEGATIVE. The output(s) are normally high (>10 volts) and go low (<1 volt) when the appropriate magnet target is in front of the sensor head. Only one of the outputs will respond in presence of a magnetic field, and it is dependent on the field polarity. MPI provides several styles of disks that contain a single magnet for this purpose, consult the factory for engine compatibility CRANK TRIGGER DISK or CAM TRIGGER DISK 1.70 MPI-0001 PIN 1: [brown] VCC (Hall Supply 15V) PIN : [white] N POLE OUT (1/REV) PIN : [blue] GROUND (SIGRTN) PIN : [black] S POLE OUT (PIP) 1 5/8-18UNF VCC PIN : N POLE VOUT PIN : S POLE VOUT 0V VCC NORTH POLE FIELD DETECTED FOR CAMREF SENSING A NORTH POLE MAGNET PIN 1: [brown] VCC (Cam Supply 15 V) PIN : [white] N POLE OUT (CAMREF) PIN : [blue] GROUND (SIGRTN) PIN : [black] S POLE OUT (not used) If a SOUTH POLE magnet is used the CAMREF signal would be on pin [black] 0V 1 SOUTH POLE FIELD DETECTED ONE MAGNET CAMDISK NOTES: 1. When using this sensor the controller must be programmed for a NEGATIVE polarity for the specific signal supplied by this sensor.. The flats must be aligned as shown to the target.. All specifications herein are applicable to the MPI p/n 0011 sensor with the exception it is a 6" reach sensor. REV DATE REV DESCRIPTION REL BY TITLE A 6/7/00 internal pull-up res,higher gauss levels axial mounted elements, 06/05/00 PRODUCTION RELEASE SHN 05/0/00 PRE-PRODUCTION RELEASE JDN DWG. NO. ORIG DATE 10/09/01 SIZE LEGAL PIN SENSOR (MPI 0001) Specification Control Drawing DRN BY SHN SCALE NONE 0001 PAGE NUM. 1 1 Murphy Power Ignition 60 RIVERDALE ST. SAN DIEGO, CA 910 TOTAL PAGES Figure 5.0 Dual Hall-effect Sensor