FUEL SYSTEMS 5 A 50830 FUEL DELIVERY SYSTEMS AND FUEL PUMPS
Tle of Contents Pge Ientifition............................. 5A-1 Replement Prts Wrning............... 5A-1 Torque Speifitions..................... 5A-1 Fuel Supply Connetions............... 5A-1 Tools / Lurints / Selnts............... 5A-1 Fuel Pressure Speifitions............... 5A-1 Preutions............................. 5A-2 Fuel Delivery System..................... 5A-2 Reommentions..................... 5A-2 Wter Seprting Fuel Filter............... 5A-3 Eletri Fuel Pump For Crurete V-6 Engine........................... 5A-4 Replement.......................... 5A-4 Fuel System Components................. 5A-4 V-6 Cruretor System................. 5A-4 V-8 Cruretor System................. 5A-5 V-6 n V-8 Throttle Boy Injetion With Cool Fuel System.......................... 5A-5 Multi-Port Injetion With Vpor Seprtor Tnk (VST)........................... 5A-6 Multi-Port Injetion With Cool Fuel System (Inlues 1997-1/2 Moel 7.4L /7.4LX / 454 / 502 / 8.2L MPI)....................... 5A-6 Replement.......................... 5A-7 Sight Tue.............................. 5A-7 Inspetion............................ 5A-7 Testing Mehnil Fuel Pump............. 5A-8 Mehnil Fuel Pump.................... 5A-8 Replement.......................... 5A-8 5A-0 - FUEL DELIVERY SYSTEMS AND FUEL PUMPS 90-806535970 1296
Ientifition Fuel Supply Connetions Mehnil Fuel Pump Replement Prts Wrning 72677 Eletril, ignition n fuel system omponents on your MerCruiser re esigne n mnufture to omply with U.S. Cost Gur Rules n Regultions to minimize risks of fire n explosion. Use of replement eletril, ignition or fuel system omponents, whih o not omply with these rules n regultions, oul result in fire or explosion hzr n shoul e voie. Torque Speifitions Fstener Lotion L. Ft. N m Fuel Pump To Sewter Pikup Pump 25 34 Fuel Lines 18 24 Fuel Fittings See Note NOTE: Refer To Fuel Supply Connetions Wrning following this hrt. Avoi gsoline fire or explosion. Improper instlltion of rss fittings or plugs into fuel pump or fuel filter se n rk sting n/or use fuel lek. Apply #592 Lotite Pipe Selnt with Teflon to thres of rss fitting or plug. DO NOT USE TEFLON TAPE. Thre rss fitting or plug into fuel pump or fuel filter se until finger tight. Tighten fitting or plug n itionl 1-3/4 to 2-1/4 turns using wrenh. DO NOT OVER-TIGHTEN. Instll fuel line. To prevent over-tightening, hol rss fitting with suitle wrenh n tighten fuel line onnetors seurely. Chek for fuel leks. Tools / Lurints / Selnts Desription Prt Numer Fuel Pressure 91-18078 Connetor (Cruretor) Quiksilver Perfet Sel 92-34227--1 #592 Lotite Pipe Selnt with Teflon Otin Lolly Fuel Pressure Guge Fuel Pressure Speifitions Desription Mehnil Fuel Pump Pressure Multi-Port Fuel Injetion With VST Throttle Boy n Multi- Port Injetion With Cool Fuel System Speifition 3-8 PSI (21-48 kp) 43 PSI (206 kp) 30 PSI (296 kp) 90-806535970 1296 FUEL DELIVERY SYTEMS AND FUEL PUMPS - 5A-1
Preutions Alwys isonnet ttery les from ttery BEFORE working on fuel system to prevent fire or explosion. Be reful when hnging fuel system omponents; gsoline is extremely flmmle n highly explosive uner ertin onitions. Be sure tht ignition key is OFF. DO NOT smoke or llow soures of sprk or flme in the re while hnging fuel filters. Wipe up ny spille fuel immeitely. Mke sure tht no fuel leks exist efore losing engine hth.! CAUTION DO NOT operte engine without ooling wter eing supplie to sewter pikup pump, or pump impeller will e mge n susequent overheting mge my result. 5A-2 - FUEL DELIVERY SYSTEMS AND FUEL PUMPS 90-806535970 1296
Wter Seprting Fuel Filter NOTICE Refer to Preutions, in this setion, BEFORE proeeing. The wter seprting fuel filter is stnr on ll engines. The fuel filter onsists of the fuel filter se n filter element. g e f h J i k 72678 Cruretor Equippe Engines - Fuel Filter Mounting Brket - Filter Element - Seling Ring l Cool Fuel System Wter Seprting Fuel Filter - Top Cover - Insultor Plte - Fuel Outlet To Throttle Boy Or Fuel Ril - Brss Fitting e - Fuel Return f - Brss Fitting g - Fuel Filter Mounting Brket h - Nut i - Inlet Fuel Fitting j - Plug k - Wter Seprting Fuel Filter l - Bottom Cover 90-806535970 1296 FUEL DELIVERY SYTEMS AND FUEL PUMPS - 5A-3
Eletri Fuel Pump For Crurete V-6 Engine NOTICE Refer to Preutions, in this setion, BEFORE proeeing. Replement IMPORTANT: The eletri fuel pump nnot e repire. If pump fils, it must e reple. Fuel System Components V-6 Cruretor System 71292 Cruretor n VST Equippe Moels - Fuel Pump - Wiring Hrness - 2 Brrel MerCr Or Weer 4 Brrel Cruretor - Eletri Lift Pump - Wter Seprting Fuel Filter - Fuel Line From Bot Fuel Tnk 5A-4 - FUEL DELIVERY SYSTEMS AND FUEL PUMPS 90-806535970 1296
V-8 Cruretor System V-6 n V-8 Throttle Boy Injetion With Cool Fuel System f g h 1 h i i e g 50830 - Fuel Tnk - Anti-Siphon Vlve - Wter Seprting Fuel Filter - Fuel Pump e - Cruretor f - Fuel Filter g - Vent Hose h - Fuel Line i - Sight Tue 1 - Bot Fuel System e f 74871 - Vent Line To Flme Arrestor - Fuel Pressure Regultor - Fuel Cooler - Eletri Fuel Pump e - Wter Seprting Fuel Filter f - Fuel From Tnk g - Diretion Of Wter Flow h - Throttle Boy Unit i - Fuel Line To Throttle Boy j - Exess Fuel Return To Wter Seprting Fuel Filter 90-806535970 1296 FUEL DELIVERY SYTEMS AND FUEL PUMPS - 5A-5
Multi-Port Injetion With Vpor Seprtor Tnk (VST) Multi-Port Injetion With Cool Fuel System (Inlues 1997-1/2 Moel 7.4L /7.4LX / 454 / 502 / 8.2L MPI) k l i e g 73895 f f g e h 74871 -Fuel Injetor (8) - Fuel Ril - Outlet Fuel Line - Return Fuel Line e - Vpor Seprtor Tnk (VST) f - Fuel Line From Wter Seprting Fuel Filter g - Wter Seprting Fuel Filter h - Fuel Line From Tnk - Vuum Line To Intke Mnifol - Fuel Pressure Regultor - Fuel Cooler - Eletri Fuel Pump e - Wter Seprting Fuel Filter f - Fuel From Tnk g - Diretion Of Wter Flow h - Throttle Boy Unit i - Fuel Line To Throttle Boy j - Exess Fuel Return To Wter Seprting Fuel Filter k - Fuel Injetors (8) l - Fuel Ril 5A-6 - FUEL DELIVERY SYSTEMS AND FUEL PUMPS 90-806535970 1296
Replement NOTICE Refer to Preutions, in this setion, BEFORE proeeing. 1. Disonnet ttery les from ttery. 2. Remove fuel filter from se. A filter wrenh my e neee to loosen element. 3. Lurite seling ring(s) of new filter with SAE engine oil. 4. Instll new filter, tightening seurely y hn. 5. Reonnet ttery les, mke sure wter is supplie to ooling system, strt engine, n hek for fuel leks. Sight Tue Inspetion Fuel pump is equippe with sight tue. Eviene of fuel in the sight tue inites rupture iphrgm n fuel pump must e reple immeitely. Vpor Seprtor Tnk (VST) - Sight Tue - Vpor Seprtor Tnk (VST) 74109 Sewter / Mehnil Fuel Pump - Sight Tue - Fuel Pump 70346 90-806535970 1296 FUEL DELIVERY SYTEMS AND FUEL PUMPS - 5A-7
Testing Mehnil Fuel Pump NOTICE Refer to Preutions, in this setion, BEFORE proeeing. 1. Disonnet ttery les from ttery. 2. Remove fuel line from ruretor or outlet sie of fuel pump. 3. Instll Fuel Pressure Connetor (91-18078) to ruretor n reinstll fuel line. Tighten onnetor n fuel line seurely. 4. Connet fuel pressure test guge to onnetor. 5. Reonnet ttery les, strt engine, n run t 1800 RPM. 6. Fuel pressure shoul e within speifitions. If not, reple fuel pump. Mehnil Fuel Pump NOTICE Refer to Preutions, in this setion, BEFORE proeeing. Replement IMPORTANT: The fuel pump nnot e repire. If pump fils, it must e reple. 72677 1. Disonnet ttery les from ttery.! CAUTION Plug fuel supply hose fter removl to prevent fuel from leking into ot. 2. Use wrenh to stilize rss oupling t fuel filter inlet fitting, loosen fuel line fitting, isonnet n suitly plug fuel line to prevent fuel in tnk from leking into ilge. 3. Remove fuel filter. 4. Using wrenh to stilize rss ouplings on fuel pump, loosen fuel line fittings n isonnet from fuel pump. 5. Clen gsket from sewter pump. 6. Apply Quiksilver Perfet Sel to oth sies of fuel pump gsket n instll on fuel pump. 7. Instll fuel pump. Torque olts to 25 l. ft. (34 N m). 8. Instll fuel inlet n outlet fittings to fuel pump s outline next: Avoi gsoline fire or explosion. Improper instlltion of rss fittings or plugs into fuel pump or fuel filter se n rk sting n/or use fuel lek. Apply #592 Lotite Pipe Selnt with Teflon to thres of rss fitting or plug. DO NOT USE TEFLON TAPE. Thre rss fitting or plug into fuel pump or fuel filter se until finger tight. Tighten fitting or plug n itionl 1-3/4 to 2-1/4 turns using wrenh. DO NOT OVER-TIGHTEN. Instll fuel line. To prevent over-tightening, hol rss fitting with suitle wrenh n tighten fuel line onnetors seurely. Chek for fuel leks. 9. Instll sight tue. 10. Instll fuel line n fuel filter. 11. Reonnet ttery les. 12. Mke sure wter is supplie to ooling system n strt engine. Chek for fuel leks. 5A-8 - FUEL DELIVERY SYSTEMS AND FUEL PUMPS 90-806535970 1296