Jeep Engines - Oljeep

T - T TINTRODUCTIONThe fuel delivery system must supply gasoline to thecarburetor/fuel injectors under very hard acceleration,potentially as high as two G. The best carburetor/fuelinjection and intake manifold set-up can’t do its job if itdoesn’t receive the proper supply of fuel. Getting fuel to thecarburetor/fuel injectors efficiently for off-road (racing)applications is the subject of this section.Note: For more information on fuel injection systems,refer to ‘Induction System’ section of this chapter.Drag Racing Fuel SystemA good electric fuel pump, such as the Carter 4.594(P4007038), should be used to make sure that the enginedoesn’t have any fuel starvation problems. It should behooked up so that it only works when the key is in the “ON”position. A separate switch in conjunction with the ignitionkey is optional. See Mopar Chassis-8th Edition (P524944 1 )for more complete details.In Stock Eliminator, one electric pump is sufficient. Infaster categories such as Super Stock or ModifiedProduction, two Carter electric fuel pumps (P4007038) inparallel should be used. Parallel means having two inletsand two outlets rather than one pump feeding into a secondpump. The mechanical pump should also be used.Also available from Mopar Performance Parts for racevehicles is a high capacity, high pressure Holley electricfuel pump (P4 120227 -regulator included) and Holleypressure regulator (P4120228). The Holley pump requiresthe Holley regulator. With the Holley pressure regulator andelectric fuel pump, you don’t use a mechanical pump. Thismeans the pump could be left on with no fuel lines attached,or the pump could be removed and the hole left in the blockcovered with a chrome fuel pump block-off plate(P4529404). The latter approach is recommended.For the majority of bracket racing applications werecommend an electric fuel pump be added next to the gastank in addition to the mechanical fuel pump. For a dual 4-Bbl. tunnel ram system, we recommend two Holley electricfuel pumps (P4120227) with a pressure regulator (includedwith pump) at each carburetor.You should always have at least one fuel filter in the linc. DONOT use a glass or plastic fuel filter. Use only a metal fuelfilter. Glass and plastic filters may be convenient, but theyare usually not legal for racing and are definitely not sqfi..4.0L POWER TECH IN-LINE 6 (FUEL DELIVERY SYSTEM) 227Fuel Delivery SystemWarning! Plastic or glass fuel filters will either melt orbreak in an accident or fire, causing a major fuel fire.MOPAR PERFORMANCE PARTS DOES NOTRECOMMEND THE USE OF GLASS OR PLASTICFUEL FILTERS AT ANY TIME.Carter Electric Fuel PumpIn Stock Eliminator, one pump is sufficient. In fastercategories, two pumps can be used in parallel. Provides 72gph 63 7.0 psi.P400703 8Carter electric fuel pump.Holley Electric Fuel PumpHigh capacity, high pressure. Can be used in parallelwithout mechanical pump for multiple carburetorapplications. Regulator included. Provides 70 gph at 9.0 psi.P4 I20227Holley electric fuel pump.Holley Fuel Pressure RegulatorTo service Holley fuel pump P4120227.P4 I20228Holley fuel pressure regulator.High Capacity Electric Fuel PumpsHigh capacity, high pressure electric fuel pump can beused singularly or in parallel with mechanical pump.Designed for drag race applications.PS249781110 gph.P.5249782 140 gph.P52497832.50 gph.Oval Track Fuel SystemThe fuel system has to keep fuel supplied in adequatevolume and pressure to allow the carburetor/fuel injectorsto function properly at W.O.T. (wide open throttle). If itdoesn’t, the engine will run lean, overheat and fail parts, ornot run at all.Caution: Due to the extreme safety hazards that electricfuel pumps can cause in oval track racing, MoparPerformance Parts does NOT recommend the use ofelectric fuel pumps for oval track vehicles. Refer to Chapter8, Off-Roading and Racing, for more details.