1984 Volkswagen Jetta GL

Transcription

1 1984 TUNE-UP Volkswagen 4-Cylinder IDENTIFICATION ENGINE IDENTIFICATION Engine can be identified by prefixes to engine serial number. Serial number is stamped on left side of engine near ignition distributor. ENGINE CODE Application Jetta, Rabbit, & Scirocco (1.7L) Quantum (1.7L) Rabbit (1.7L Carbureted) Rabbit GTI (1.8L) Code EN WT FX JH TESTING ENGINE COMPRESSION Check compression with engine warm, all spark plugs removed and throttle wide open. Crank engine through at least 6 compression strokes per cylinder to determine engine compression. CAUTION: On models with electronic ignition, connect coil high tension wire to ground before cranking engine. COMPRESSION SPECIFICATIONS Application Specification Compression Ratio Rabbit GTI 8.5:1 All Others 8.2:1 Compression Pressure Maximum psi ( kg/cm 2 ) Minimum 102 psi (7.0 kg/cm 2 ) Max. Variation Between Cylinders 44 psi (3.0 kg/cm 2 ) SPARK PLUGS SPARK PLUG TYPE SPECIFICATIONS Application Bosch No. Champion No. Federal (1) W7D N8Y Jueves, 31 de Mayo de :44:57 04:45:03 p.m. Page Mitchell Repair Information Company, LLC.

2 Calif. WR7DS N8GY (1) Federal Rabbit GTI and Quantum uses WR7DS (Bosch) or N8GY (Champion). SPARK PLUG SPECIFICATIONS Gap: In. (mm) Torque: Ft. Lbs. (N.m) (0.70) 14 (22) HIGH TENSION WIRE RESISTANCE Remove distributor cap and disconnect high tension wires from spark plugs (not distributor cap). Using an ohmmeter, measure resistance from cap terminal to other end of wire. If resistance is not to specifications, or fluctuates when wire is twisted gently, replace wire(s). NOTE: High tension wire resistance cannot be measured if wire ends are marked with the following symbol: HIGH TENSION WIRE RESISTANCE SPECIFICATIONS Application Ohms All Models FUEL PUMP To test fuel pump on all models (except carbureted), disconnect fuel output line and apply 12 volts to fuel pump. CAUTION: Do not touch positive connection to ground. FUEL PUMP PERFORMANCE SPECIFICATIONS Application Pressure psi (kg/cm 2 ) Volume in 30 seconds Pints (Liters) Rabbit (Carbureted) ( ) N/A All Others ( ) 8.4 (1.0) ADJUSTMENTS VALVE CLEARANCE 1. Valve clearance is between the cam lobe and cam follower. 2. Clearance is adjusted by means of replaceable discs. Discs are available in 26 thicknesses from " ( mm). Discs most frequently used are " ( mm). 3. To adjust, warm up engine to normal operating temperature. Using wrench on center bolt of crankshaft pulley, hand turn crankshaft clockwise until cam lobes for cylinder being tested are pointing upward. Use feeler gauge to check valve clearance. Jueves, 31 de Mayo de :44:57 p.m. Page Mitchell Repair Information Company, LLC.

3 4. Use Depressor (2078) to press down cam follower, so that adjusting disc can be readily removed with Pliers (US 4476). When depressing cam followers, turn so that openings are at a 90 angle to cam. VALVE CLEARANCE SPECIFICATIONS Application In. (mm) Intake ( ) Exhaust ( ) VALVE ARRANGEMENT E-I-E-I-I-E-I-E (Front-to-rear). DISTRIBUTOR All models use Bosch electronic breakerless ignition systems. No adjustments are required. Fig. 1: Firing Order & Distributor Rotation Jueves, 31 de Mayo de :44:57 p.m. Page Mitchell Repair Information Company, LLC.

4 Fig. 2: Ignition Timing Mark Locations (All Models) - Adjust Timing By Turning Distributor IGNITION TIMING (EXCEPT QUANTUM) Special Coil Although the kinds of ohmmeters commonly used in automotive electrical testing lack the sensitivity required, you can test the special coil with sensitive ohmmeters such as those used in radio and TV repair work. If the Jueves, 31 de Mayo de :44:57 p.m. Page Mitchell Repair Information Company, LLC.

5 measured resistance are outside the ranges given in, the special coil should be replaced with a special new coil (Part No B). Ignition Control Unit & Digital Idle Stabilizer The ignition control unit is a transistorized device with two basic functions. First, it receives and amplifies the triggering pulses generated by the distributor's Hall sending unit. Second, it switches on and off the 12-volt primary current by means of a switching transistor that is actuated by the amplified signals from the distributor. Additionally, the ignition control unit has a device that limits the duration of the primary current that is sent to the coil. (In effect, this is variable dwell.) By doing this, the control unit supplies a more powerful spark under full engine loads that demand it, and saves electrical energy by reducing the spark's power at idle and under light loads. This reduction of electrical load not only serves to reduce the current demands of the ignition systems but also to extend the service life of the spark plugs and of other ignition system components. The digital idle stabilizer (DIS) is used only on cars with carburetors and on cars with fuel injection when sold in California. If there is ignition system trouble on a vehicle with DIS, disconnect both plugs from the DIS with the engine stopped. Then connect the plugs together, and start the engine. If the trouble goes away (and if the trouble is not poor contact between the plugs and the DIS), then the DIS is faulty and should be replaced. The function of the DIS is to keep the engine idle speed in the same RPM range at all times, regardless of the added load that might be placed on the engine by turning on the A/C or engaging a drive range for the A/T. It does this by monitoring engine RPM signals from the ignition distributor. When the idle speed falls below 840 RPM, the DIS advances the ignition timing automatically to return the idle speed to the correct range. Because the DIS works only between 600 and 840 RPM, it does not affect ignition timing during starting or after the throttle has been opened. Testing 1. To test the special coil, replace faulty coils. On vehicles with digital idle stabilizer, disconnect both plugs from the digital idle stabilizer and connect the plugs together. 2. Detach the multiple connector from the control unit and connect a voltmeter. Turn on the ignition. If battery voltage is not indicated approximately there is trouble in the ignition switch or the wiring, which you can troubleshoot using appropriate wiring diagram in the WIRING DIAGRAMS Section. 3. Turn off the ignition. Reconnect the multiple connector to the control unit. 4. Disconnect the wiring between the distributor and the control unit by detaching the multiple connector from the distributor. The distributors have a wire clip that you must pry aside before you can detach the wiring. 5. Connect the positive (+) test lead of a voltmeter to terminal 15 of the special coil: connect the negative (-) test lead to terminal Turn on the ignition. The voltmeter should indicate a minimum of 2 volts for about 1 or 2 seconds and then drop to zero volts. If it does not, turn off the ignition and replace the control unit and the special coil before repeating test. 7. Turn on the ignition. Using a jumper wire or a metal pin, briefly ground the central terminal of the multiple connector disconnected from the distributor to some clean, unpainted metal part of the engine. If the voltage at the coil does not increase briefly to at least 2 volts, check for breaks in the wire attached to the multiple connector's central terminal. If no fault is found in the wire, turn off the ignition and replace Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

6 the control unit. 8. With the ignition off, connect a voltmeter to the two outermost terminals of the multiple connector disconnected from the distributor. Turn on the ignition. If at least 5 volts are not indicated, check for breaks in the wires attached to the multiple connector's outermost terminals. If no fault is found in the wiring, turn off the ignition and replace the control unit. Reconnect the digital idle stabilizer (where applicable) when testing is complete. Breakerless Distributor The breakerless distributor is similar in appearance to a conventional ignition distributor. Servicing, however, is simplified by the absence of breaker points or a condenser so that it is necessary only to check and possibly replace the rotor and the cap, check the spark advance mechanism, and adjust the ignition timing. Because there is no breaker point wear or misadjustment possible, the ignition timing seldom requires actual adjustment unless the distributor has been removed and reinstalled or the camshaft drive belt replaced. Hall Sending Unit The Hall sending unit inside the distributor is the most easily tested component in the transistorized breakerless ignition system. Although a voltmeter is specified for the test in the procedure that follows, you can use a test light for all testing if you lack a voltmeter. Hall Sending Unit Testing 1. Test the special coil and the control unit as previously described. During the control unit test, check the wiring thoroughly and make certain that the terminals of the multiple connector at the distributor are clean and tight-fitting. 2. On vehicles that have a digital idle stabilizer, disconnect both plugs from the digital idle stabilizer and connect the plugs together. If necessary, See Fig. 3 -Fig. 7. Also disconnect the high tension cable from terminal 4 at the center tower of the distributor cap. Using an adaptor cable, solidly ground the disconnected high tension cable to some clean, unpainted metal part of the engine. This is to keep the engine from starting while you hand-turn the crankshaft in step If necessary, turn off the ignition. Slide the rubber boot off the multiple connector for the control unit, and connect a voltmeter as indicated in Fig Turn on the ignition. While you observe the voltmeter, use a wrench on the bolt in the center of the crankshaft pulley to hand-turn the pulley clockwise-thus turning the crankshaft in its normal direction or rotation. The voltage should fluctuate between at least 2 volts (Hall sending unit rotor aperture closed) and 0 volts (rotor aperture open). 5. If the voltage did not fluctuate as specified in step 4, replace the Hall sending unit. With the ignition off, reconnect the digital idle stabilizer and the high tension cable when testing is complete. Then disconnect the voltmeter and reinstall the boot on the control unit's multiple connector plug. Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

7 Fig. 3: Voltmeter Hookup For Distributor Voltage Check Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

8 Fig. 4: Checking Hall Control Unit Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

9 Fig. 5: Checking Hall Control Unit Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

10 Fig. 6: Voltmeter Hookups For Hall Generator Check Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

11 Fig. 7: Ohmmeter Hookups For Resistance Checks NOTE: If a new Hall sending unit, called an impulse coil in the parts lists, is unavailable, you should replace the breakerless distributor as a unit. Disassembling & Assembling Distributor One or two screwdrivers, and possibly snap ring pliers, are the only tools required for disassembling the breakerless distributor. Although it is possible to disassemble the base plate, the centrifugal advance mechanism, and the distributor shaft for cleaning and inspection, replacement shafts, centrifugal advance parts, and base plates are not supplied as replacement parts. To remove the Hall sending unit, remove the distributor cap, the suppression shield assembly, the rotor, and the shield plate. Using snap ring pliers, remove the snap ring from atop the trigger wheel. Then use two screwdrivers positioned at opposite sides of the trigger wheel to pry the trigger wheel out. The Hall sending unit can be removed from the base plate by removing the screws and taking off the remaining washers and snap rings. To remove the base plate, first take out the screws and remove the vacuum unit and the spring steel cap retainers. After removing the remaining screw that passes through the side of the distributor housing, you can lift out the base plate for access to the centrifugal advance mechanism. During assembly, lightly lubricate the friction surfaces of the base plate with multipurpose grease. Lubricate the centrifugal advance mechanism with engine oil; also applying engine oil to the felt wick that is in the center of the distributor shaft. During routine servicing, you should be sure that this felt wick is saturated with engine oil. Timing Adjustment Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

12 You should adjust the ignition timing whenever the distributor has been removed and reinstalled or after installing a replacement Hall sending unit. Incorrect timing can cause decreased fuel economy and excessive exhaust emissions. 1. On vehicles with M/T, use a special wrench (VW tool US 4463) to remove the plastic plug from the timing check hole at the top of the transaxle's flywheel bellhousing. NOTE: You must remove the entire plug by unscrewing it with a wrench that fits the hexagonal recess. You will not see the timing marks if you snap out only the small central plug which is for the temporary insertion of a computer analysis sensor. 2. Connect a tachometer. Then, following the instrument manufacturer's instruction, install a stroboscopic timing light. 3. Start the engine and allow it to warm up until the oil temperature is at least 80 C (176 F). If the idle speed of a fuel injection engine sold outside Calif. (no digital idle stabilizer) is not between 850 and 1000 RPM. Adjust Idle. 4. On engines with digital idle stabilizers, stop the engine. Then detach both plugs from the digital idle stabilizer and connect the plugs together (These plugs are present on some other vehicles, but they are connected together at the factory.) 5. On engines with carburetors, disconnect the vacuum retard hose only from the ignition distributor's vacuum unit and plug the hose. On 1984 models, clamp the idle bypass hose. 6. Start the engine and allow it to idle. Then check the idle speed. On fuel injection models, the idle speed should be between 850 and 1000 RPM. 7. Aim the timing light at the timing check hole in the bellhousing. Illuminated by the timing light, the timing mark should appear stationary adjacent to the pointer in the hole. NOTE: U.S.-built Rabbits have flywheels with Fuel Injection and 5-Speed transmission have an incorrect timing mark at 3 ATDC. Make a new mark at 6 BTDC 12 mm (0.47 in.) left of TDC. 8. If the timing mark is not correctly aligned with the pointer, loosen the ignition distributor's hold-down bolt. Then, with the engine idling between 800 and 1000 RPM hand-turn the distributor housing clockwise or counterclockwise until the mark is aligned with the pointer. 9. Where applicable, reconnect the vacuum retard hose. The idle speed should drop by abut 200 RPM into the idle speed adjusting range. 10. Stop the engine. On engines with digital idle stabilizers, disconnect the plugs from one another and reconnect them to the digital idle stabilizer. 11. On vehicles with digital idle stabilizers, restart the engine. Accelerate it to about 2000 RPM and then allow the engine to return to an idle. With the digital idle stabilizer connected, the RPM should stabilize between 850 and 1000 RPM (with fuel injection). 12. If necessary, stop the engine. Then disconnect the tachometer and the timing light. Checking Spark Advance Mechanism Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

13 The breakerless distributor has both a centrifugal spark advance mechanism and a vacuum spark control that incorporates a vacuum retard and a vacuum advance. Special timing lights are available that incorporate a builtin meter you can use to measure spark advance. The instructions supplied with these timing lights tell you how to use the device to check the centrifugal advance mechanism. By using the special timing light in conjunction with a vacuum gauge (attached to T-fittings inserted in the two hoses that are connected to the distributor), you can also check the vacuum advance and the vacuum retard. TABLE C, TABLE D, TABLE E list the RPM and vacuum levels where critical changes in the spark advance and spark retard curves take place. The distributor number is stamped on the distributor itself. Comparing actual distributor operation to the data in the table will help you to locate dirty, binding advance mechanisms, or mechanical faults in the distributor. If testing reveals irregularities in the spark advance curve, first clean and lubricate the moving parts of the distributor. If the vacuum advance still fails to conform to specifications, install a new vacuum unit. If retesting reveals discrepancies in the centrifugal advance curve, it indicates worn internal parts. In that case, you should replace the distributor body and internal parts as a unit. TABLE C: CENTRIFUGAL SPARK ADVANCE CURVES FOR BREAKERLESS DISTRIBUTOR Distributor P/N (Crankshaft RPM) Degrees Crankshaft R (Canadian Cars, P/U Trucks) Advance Begins D (Engines Code Letter JH) Advance Begins TABLE D: VACUUM SPARK ADVANCE CURVES FOR BREAKERLESS DISTRIBUTOR Distributor P/N (Vacuum (1) ) Degrees Crankshaft R (Canadian cars, P/U Trucks) ( , ) Advance Begins ( , ) 4-8 Maximum D (Engines Code Letter JH) (90-120, ) Advance Begins ( , ) Maximum (1) Vacuum in mbar (mm/hg, in./hg). TABLE D: VACUUM SPARK ADVANCE CURVES FOR BREAKERLESS DISTRIBUTOR Distributor P/N (Vacuum (1) ) Degrees Crankshaft R (Canadian cars, P/U Trucks) (95-180, ) Retard Begins Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

14 ( , ) 8-10 Maximum B & D (2) (1) Vacuum in mbar (mm/hg, in./hg). (2) These distributors have no vacuum retard device. IGNITION TIMING (QUANTUM) 1. Make sure engine oil temperature is at least 140 F (60 C). On models with carburetor, disconnect and plug distributor vacuum hose. On all other models, leave distributor vacuum hoses are connected. Attach timing light to engine. Disconnect idle stabilizer control unit connectors, and connect them together. 2. Make sure idle speed and timing are set to specifications. If timing is not to specifications, adjust by turning distributor. Reconnect idle stabilizer connectors, distributor vacuum hose (if removed) and remove test equipment. IGNITION TIMING SPECIFICATIONS DEGREES RPM Application Man. Trans. Auto. Trans. Quantum (1) (2) (1) Ignition timing is RPM on carbureted models. (2) BTDC. IDLE SPEED & MIXTURE NOTE: Mixture adjustment is NOT a part of normal tune-up procedure and should not be performed unless carburetor or mixture control unit is replaced or vehicle fails emissions testing. Carbureted Models 1. Warm engine to operating temperature. Ensure choke is fully open. Remove PCV valve from valve cover. Disconnect idle stabilizer plugs and connect together. Connect a tachometer and CO meter to engine. NOTE: Oxygen sensor is connected during CO checking and adjustment. 2. Connect dwell meter to oxygen sensor system receptacle (Blue/White wire) near right front strut tower. Start engine and accelerate to 2000 RPM for 5 seconds. Check idle speed and adjust using screw on throttle lever. 3. Dwell reading should fluctuate within range of at sea level. Reading will increase about 4 for each 1000 foot increase in elevation. CO reading should be less than 1.5%. If dwell or CO% is incorrect, remove carburetor from engine. Remove tamper-proof plug from idle mixture screw. 4. Reinstall carburetor and adjust idle mixture screw to obtain correct readings. Turning screw clockwise lowers duty cycle dwell reading. Turning counterclockwise raises reading. 5. Reading must fluctuate if oxygen sensor is working. Install tamper-proof plug in carburetor. Shut engine Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

15 off, disconnect test equipment and reconnect all hoses. NOTE: Mixture is adjusted using VW 1367 dwell meter. CO meter is used to verify that oxygen sensor system operates properly. Fuel Injected Models 1. Remove both connectors from idle stabilizer and connect them together. Run engine until oil temperature is above 176 F (80 C). Disconnect and plug PCV hose so fresh air can enter system. Turn off all electrical equipment. 2. On Quantum models, remove cap from "T" piece in charcoal canister vent hose near right fender well. On all other models, remove charcoal canister vent hose at elbow below intake boot. 3. Connect CO meter to CO test point on engine using Adapter Hose (US 4492). Start engine and briefly accelerate. Check idle speed and adjust as necessary. Check ignition timing and adjust. 4. Connect dwell meter to oxygen sensor test connection. Plus lead of dwell meter goes to Blue/White wire and negative lead goes to ground. Set dwell meter on 4-cylinder scale. Briefly accelerate engine. At sea level, dwell reading should range between with oxygen sensor connected. 5. If not, adjust dwell ratio. Remove intake air sensor. Center punch the plug in CO adjusting hole. Using a 3/32" drill bit, drill hole 5/32" deep in center of plug. Remove any metal shavings. 6. Screw in a sheet metal screw and remove plug with screw, using pliers. Reinstall intake air sensor. Remove plug from air sensor housing. Insert Adjusting Adapter (P377) and adjust dwell with mixture adjusting screw. Dwell reading will fluctuate. Adjust so reading displays Install a new tamperproof plug. If dwell does not fluctuate check oxygen sensor system. 7. Disconnect oxygen sensor, dwell should be steady between and CO value should be.3-3.0%. If CO value is too high, check for leaks in intake system and exhaust system. Also check fuel system for a malfunction. Adjust if necessary. 8. Reconnect oxygen sensor and recheck idle speed. Stop engine, reconnect PCV hoses, charcoal canister hose and idle stabilizer. IDLE SPEED & CO LEVEL SPECIFICATIONS Application Idle RPM CO% Quantum Rabbit (Carbureted) All Others COLD (FAST) IDLE RPM Carbureted Models Warm engine to operating temperature. Stop engine. Disconnect electric purge valve connector and EGR valve. Set fast idle lever on second step of the fast idle cam. Start engine and adjust fast idle speed to 2800 RPM. SERVICING EMISSION CONTROL Jueves, 31 de Mayo de :44:58 p.m. Page Mitchell Repair Information Company, LLC.

16 See EMISSIONS section. SPECIFICATIONS IGNITION Distributor All models use Bosch electronic breakerless ignition systems. IGNITION COIL RESISTANCE (OHMS) SPECIFICATIONS Primary Secondary FUEL SYSTEM Fuel Injection All models use Bosch Lambda CIS fuel injection with oxygen sensor. Carburetor Rabbit models with carburetor use a Carter TYF 1-Bbl. BATTERY BATTERY SPECIFICATIONS Application Amp Hr. Rating Jetta, Quantum, Rabbit Convertible & Scirocco 45 Rabbit, Rabbit GTI, 54 STARTER All models are equipped with Bosch starters. ALTERNATORS All models are equipped with Bosch or Motorola alternators with integral voltage regulators. ALTERNATOR SPECIFICATIONS Application Rated Amp Output All Models 65 ALTERNATOR REGULATOR All models are equipped with Bosch or Motorola alternator regulators. Regulators are not adjustable. Jueves, 31 de Mayo de :44:59 p.m. Page Mitchell Repair Information Company, LLC.

17 SERVICE SPECIFICATIONS BELT ADJUSTMENT Application (1) Deflection In. (mm) All Belts Length Less Than 39.4" (1m) (2-5) Length More Than 39.4" (1m).4-.6 (10-15) (1) Deflection is measured with moderate thumb pressure applied midway on longest belt run. REPLACEMENT INTERVALS Component Service Interval (Miles) Oil Filter 15,000 Air Filter 30,000 Fuel Filter Quantum (1) & Scirocco 60,000 All Others 15,000 Spark Plugs 15,000 (1) Discard Mini-Fuel filter at 1000 mile maintenance. Install new copper gaskets. FLUID CAPACITIES Application Crankcase (Including Filter) Quantum All Other Models Cooling System Jetta & Scirocco Quantum Rabbit, Rabbit GTI Man. Transaxles (SAE 80W-90) 4-Speed 5-Speed Auto. Transaxle (Dexron) Auto. Transaxle Differential (SAE 90) Fuel Tank Jetta & Scirocco Quantum Rabbit & Rabbit GTI Quantity 3.5 qts. (3.0L) 4.8 qts. (4.5L) 5.0 qts. (4.8L) 6.5 qts. (5.5L) 7.0 qts. (6.5L) 3.2 pts. (1.5L) 4.2 pts. (2.0L) 6.4 pts. (3.0L) 1.6 pts. (0.8L) 10.5 gals. (40.0L) 16.0 gals. (60.0L) 10.0 gals. (38.0L) Jueves, 31 de Mayo de :44:59 p.m. Page Mitchell Repair Information Company, LLC.