Ive been reading about the 4.0 head swap for 4.2 motors. Is this really as good as it sounds or are there more headaches to be found?
What all has to be replaced besides the head?
Have to be fuel injected then?
40hp gain? really?Ive been reading about the 4.0 head swap for 4.2 motors. Is this really as good as it sounds or are there more headaches to be found?
What all has to be replaced besides the head?
Have to be fuel injected then?
40hp gain? really?
It depends on whether the 4 liter head takes the same intake as the
4.2. If not there may be a carb manifold or, you could fabricate one were you so inclined. Even if you are not a highly skilled welder, you could learn enough gas (oxy-acy) welding to tack it and have it done by a pro.Three Webers, that's the shit.
As is so often the case we fail the reading Comprehension Test.
JEEP 4.2 LITER (258 CID) MULTIPOINT FUEL INJECTION KIT
INSTALLATION INSTRUCTIONS
Mopar PERFORMANCE
INSTALLATION INSTRUCTIONS
JEEP 4.2 LITER (258 CID) MULTIPOINT INJECTION KIT P5249610 For Manual Transmission Vehicles P5249686 For Automatic Transmission Vehicles
THIS KIT IS EMISSIONS EXEMPT IN THE STATE OF CALIFORNIA UNDER C.A.R.B. EXECUTIVE ORDER D265-7 THE TUNE UP PROCEDURES AND ENGINE SERVICE ARE THE SAME AS A 1994/1995 4.0 LITER JEEP WRANGLER
PLEASE READ THESE INSTRUCTIONS THOROUGHLY PRIOR TO INSTALLATION OF THIS KIT
CHECK YOUR PARTS AGAINST THE BILL OF MATERIAL INCLUDED IN THE KIT (Attached to instructions)
This product is intended for use on STOCK, UNMODIFIED, WELL MAINTAINED
1981-1990 4.2 LITER (258 cid.) ENGINES. Installation on engines with MODIFIED CAMSHAFTS, INCREASED COMPRESSION RATIO or engines that are in POOR MECHANICAL CONDITION, such as LOW CRANKING COMPRESSION or EXCESSIVE OIL CONSUMPTION is not recommended.NOTE: If spark knock (detonation) occurs, it is recommended that 92 octane or better premium fuel be used. The use of Mopar combustion chamber cleaner will reduce carbon deposits and help reduce spark knock.
DISASSEMBLY:
1=2E Disconnect the ground cable from the battery and drain the coolant from the radiator.2=2E Loosen the power steering pump and the alternator and remove the drive belts. Remove the two bolts that hold the power steering pump to the water pump. Remove the two nuts from the rear power steering pump bracket, then slide the pump forward to disengage it from the rear bracket. Remove the rear bracket from the intake manifold.
3=2E Remove the air cleaner assembly as a unit and discard it.4=2E Remove all of the production emissions controls from the engine, including the three (3) solenoids located on top of the valve cover, the vacuum switch assembly and any lines and delay valves connected to the carburetor.
NOTE: Refer to the Production Emissions Schematic or to a proper shop manual for your particular year vehicle.
5=2E Remove the pulse air valves, which inject fresh air upstream and downstream of the catalytic converter, and all associated fittings.6=2E Disconnect the heater hose from the fitting on the intake manifold. Remove the throttle linkage and throttle cable. Remove the carburetor/intake manifold assembly. This will require removing the tube that connects the exhaust manifold to the EGR valve mounted on the intake manifold.
NOTE: It is not necessary to remove the exhaust manifold.
7=2E Remove the stock mechanical fuel pump and fuel lines from the engine. Make sure to mark the lines PRESSURE and RETURN where you disconnect them at the fender well.CAUTION: GASOLINE IS HAZARDOUS!! Wear eye protection and never work on a HOT engine or around FIRE OR FLAME!
8=2E Disconnect the upper and lower radiator hoses and remove the radiator, fan shroud, engine fan, thermostat housing and crankshaft pulley.9=2E Remove the plug wires and distributor cap. Remove the #1 spark plug and rotate the engine in its normal direction until the #1 piston is on the compression stroke. The timing mark on the dampener should line up with the "O" mark on the timing tab. Looking through the stock fuel pump mounting boss, rotate the engine backwards until the camshaft moves and note the amount of slack in the timing chain as degrees on the timing tab. If the slack is more than 10 degrees, replace the timing chain. Rotate the engine in the direction of rotation to the "O" of the timing tab. Note the clocked position of the distributor rotor. Loosen the hold down clamp and remove the distributor. Remove the ignition coil and bracket and discard them.
ASSEMBLY:
1=2E Install the new oxygen sensor in the exhaust manifold.2=2E Cut off one end of the tube that went from the exhaust manifold to the EGR valve and remove the tube nut from it. Install the saucer shaped freeze plug into the hole in the exhaust manifold where you removed the EGR tube. Secure the freeze plug by tightening the now free tube where nut down against the freeze plug.
3=2E Install the new distributor (The distributor is shipped with an indexing lock pin and will not rotate. DO NOT REMOVE THE PIN UNTIL THE DISTRIBUTOR IS INSTALLED).NOTE: If you think the engine may have moved from TDC, make sure the engine is at TDC on the crankshaft balancer. Install the hold-down clamp and remove the white locking pin.
4=2E Install teh conbination fuel pump block-off plate/ignition coil bracket where you removed the original fuel pump. Install the coil with the plug wire terminal toward teh distributor.5=2E Install the new crankshaft dampener. (Torque the bolt to 120 ft. lb.)
6=2E Install the pickup sensor bracket. The bracket bolts to the oil pan where you removed the three (3) bolts in step #13 of the disassembly instructions. Install the pickup sensor on the bracket with the bolt provided. NOTE: There should be between .020" and .060" clearance between the sensor and the crankshaft dampener. This clearance is the thickness of the paper button on the end of the sensor. You push the sensor up against the dampener, then tighten the mounting screw. This will set the initial clearance.7=2E Install the crankshaft pulley, the fan, and the radiator. Install the new
195 degree thermostat. This is critical. Temperature level of 195 degrees is critical for fuel system operation. Install the coolant sensor supplied into the new thermostat housing in the 3/8" pipe hole, then reinstall this new assembly on the engine. Reinstall the radiator hoses and heater hoses; reroute the new heater hose supplied, as it no longer goes through the intake manifold.8=2E Install the new intake manifold. You will only be able to reinstall one of the power steering pump bracket bolts and You may have to trim the top lip off of the power steering pump bracket to make it fit the new manifold. DO NOT over tighten the bolts! Bolt torque is 23 ft. lb.
9=2E Install the throttle cable and bracket.
NOTE: On models with the fuel supply line on the right side, carefully route the line around to the fuel rail similar to the O.E. setup.
CAUTION: If you buy any fuel line to hook up the fuel pump, make sure it is rated to handle EFI pressures!
INSTALL FUEL PUMP AS FOLLOWS:
13A. Jack up the rear of the vehicle and place on jack stands. From under the vehicle looking to the rear you will notice a cross member in the frame above and behind the axle housing. On the driver's side of this cross member you will notice a rubber block with three (3) flexible fuel lines emerging from it. The lines turn 90 degrees toward the frame and are connected to hard lines with clamps. On the flange of the cross member are three (3) bolts that attach the fuel tank skid pan to the cross member.13B. Remove the center bolt.
13C. Disconnect the center fuel line from its hard line at the clamp. Reconnect this flexible line to the inlet of the new fuel pump assembly using the same clamp.13D. Mount the fuel pump assembly to the cross member flange using the nut and lock washer.
13E. Connect the 5/16" flexible line coming off the new fuel pump assembly to the fuel filter inlet line, with the clamp provided, and the fuel filter outlet to the center hard line of the original fuel line.
CAUTION: THE HARNESS MUST NOT BE CLOSE TO THE EXHAUST, USE TIE WRAPS TO SECURE IT OVER THE MASTER CYLINDER.
NOTE: Make sure that the switched 12 volt wire is not routed thru a ballast resistor or resistance wire. Also make sure that 12 volts are present on this wire during cranking!
TROUBLE SHOOTING NOTES: Hints we have found useful
1=2E This system is the same as used on the 1994 4.OL Wrangler. If you need service parts, or are checking fault codes, refer to the 1994 Jeep Wrangler Service Manual. The wiring is also the same as a 1994 Wrangler in function and color. You may call 1-800-626-1523 to order a service manual.2=2E The crankshaft sensor is very sensitive. Make sure it is solidly mounted. Make sure that your engine does not have too much crankshaft end play. The paper button on the sensor will wear off with use of the engine.
3=2E The distributor should not be turned to change timing. It will not. The distributor is set to have the rotor tip .020' past #1 spark plug terminal with the engine at TDC.4=2E The fuel return line to the tank must be unrestricted. Check this carefully before you hook up the return hose.
5=2E You may see fault codes for charging system too high or too low. This is normal and should be ignored.6=2E The PCM does take some time (15 - 30 minutes) after first use to "learn" the best settings for your engine. You will notice better idle quality and acceleration after this learning period. For this reason, the battery should be left connected if this vehicle is to be driven daily. If you use a kill switch, do not interrupt the B+ circuit or the PCM will need to "re-learn" every time you start the engine.
MANUAL TRANSMISSION P5249610 MPI KIT PACKING LIST
DESCRIPTION PART # QUA. DESCRIPTION PART# QUA.
1) WIRING HARNESS P4532698 1 51) THROTTLE BODY 04856107 * 1 2) THERMOSTAT HOUSING 53006192 1 52) THROTTLE BODY GASKET 53007543 * 1 3) COOLANT SENSOR 33004281 1 53) 3/16' VACUUM CAP 9400049 * 1 4) INTAKE MANIFOLD 9400045* 1 54) FUEL LINE CLIP 34202997 * 1 5) FUEL INJECTOR CLIPS 04418257* 6 55) VACUUM PORT 53004523 * 1 6) FUEL INJECTOR 53030343* 6 56) SPEED SENSOR 56027015 * 1 7) FUEL INJ LINE-INLET 52018416 1 57) MAP SENSOR BRACKET 56027080 1 8) FUEL INJ LINE-RETURN52018417 1 58) 5/8"X7/8" SPEEDO ADAPT 9400012 * 1 9) FUEL PRESSURE REG 53030001* 1 59) 1/2" PCV HOSE 9400048 2 10) FUEL RAIL ASSEMBLY 53030435 1 60) 1/2" PLASTIC HOSE SPLC 9400016 2 11) THROTTLE CABLE 52079382 1 61) 3/16" TUBE X 1/4" NPT 9400018 * 1 12) THROTTLE CABLE BRCKT 53007486* 1 62) #10 X 1/2" SHEET METAL SCREW 9400020 4 13) COIL BRKT & FUEL PMP PLATE P4532710 1 63) 1/4" TUBE X 1/4" NPT 9400019 * 2 14) IGNITION COIL 04797293 1 64) M5 X 20MM CAP SCREW 9400021 * 1 15) SPARKPLUG WIRE SET 83507178 1 65) 1/4" NC X 1-1/4" CAP SCREW 9400025 2 16) OXYGEN SENSOR 56028301 1 67) 1/4" NC X 1 l/2" CAP SCREW 9400022* 1 17) CRANK SENSOR 56026884* 1 68) M6 X 20MM CAP SCREW 9400023 * 4 18) THROTTLE BODY ELBOW 53006289 1 69) M8 X 20MM CAP SCREW 9400024 * 1 19) THROTTLE BODY CLAMP 53008274 2 70) 5/16" X 1" CAP SCREW 9400030 * 1 20) FUEL PUMP-ELECTRIC P4532709 1 71) M5 FLAT WASHERS 9400027 * 3 21) FUEL FILTER 33000076 1 72) M6 FLAT WASHERS 9400028 * 11 22) FUEL HOSE-18"X5/16" 9400047 1 73) 5/16" FENDER WASHER 9400029 * 1 23) FUEL PUMP CLAMP MNT 9400009 1 74) 5/16"X1-1/4" CAP SCREW 9400030 * 1 24) HOSE CLAMPS 5/16" 9400002 9 75) M8 LOCK WASHER 9400031 * 1 25) INTAKE HOSE-CAT 18" X 2-3/4" 9400008 1 76) M5 HEX NUTS 9400032 * 2 26) AIR FILTER ADAPTER 9400007* 1 77) 1/4" NC NYLOC NUTS 9400034 * 2 27) K&N AIR FILTER 9400003 1 78) 5/16" NC NYLOC NUTS 9400035 * 28) CLAMP 2-3/4" WORM 9400013 2 79) 3/16" VACUUM HOSE 9400036 * 1 29) ADAPTER HOLDDOWN CLAMP 9400006 1 80) 2.5" ADEL CLMP (FUEL FILTER) 9400037 1 30) INTAKE HOSE ADAPTER 9400005 1 81) 1/4" NC X 1" CAP SCREW 9400039 2 31) VENT TUBE 1/2" X 3/8" X 90' 9400010 2 82) 3/16" FLAT WASHER 9400040 2 32) CRANK SENSOR BRACKET 9400004* 1 83) 1/4" FLAT WASHER 9400041 3 33) MAT SENSOR 33004280* 1 84) CONCAVE EXPANSION CUP 9400042 1 34) MAP SENSOR 33000153 1 85) INSTALLATION INSTRUCTS 9400043 1 35) FUEL CANNISTER 53030500 1 86) DIODE SPLICE 9400044 1 36) TIE WRAPS 4" 9400014 1 87) #10 X 2" SHEETMETAL SCREWS 9400015 3 37) THERMOSTAT 4494469 1 88) VACUUM TUBE 53006237 1 38) DISTRIBUTOR 9400046 1 89) UNDER HOOD EMISSION DECAL 9400050 39) M6 X 14M CAP SCREW 9400052 7 90) 3/8" MOUNTING CLAMP 9400054 40) VALVECOVER FITTING (GRAY) 5303G497 1 41) VALVECOVER FITTING (BLACK) 53030495 1 42) VACUUM TUBING 53030728 1 43) BRACKET-FUEL CANNISTER 53009759 1 44) VACUUM TUBE 53006226 1 45) VACUUM TUBE 53030473 1 46) VACUUM TUBE 53030474 1 47) ECM MANUAL TRANSMISSION P4532679 1 48) M5 X 30M CAP SCREW 9400011* 2 49) FUEL PRESS. REG. CLAMP 04418897* 1 50) INTAKE MANIFOLD GASKET J3242855 1
Getting rid of the EFI is the idea, not keeping it.
This EFI is designed for one specific engine as outlined in the text. If you put the 4 liter head on the 258 lower what you get is not that engine.
An aftermarket EFI controller using a Ford MAF sensor AND a MAP sensor AND providing RS-232 link to a laptop is way, way, way better. There was a good article in Grassroots motorsports magazine addressing this.
Of course plugging the injector holes and putting a propane mixer on there works too.
I added the Electronic Fuel injection in case he came to his senses. I realize common sense is not one of your forte God Bless America, Bill O|||||||O mailto: snipped-for-privacy@aol.com
Fuel injection systems aren't Mopar's forte, to judge from the factory kit.
If you are willing to trust some glue to hold all the coolant in, then it might be a good thing. You can use the 4.2 intake, but the exhaust manifold has to be 4.0.
All these guys that do any mods to the 4.2 like that head job or the FI job all claim this big HP increase. Well... you get the same increase they are crowing about for free by just killing the emissions computer on the 82's to 91's, which by the way they have to do anyway for the mods... LOL!
The rpm 'red line' goes from about 3300 rpm to 4400 and you get at least a 10 mph increase in each gear.
My 86 CJ7 will just light up my 33's off the start if I punch it, it then hits about 52 mph in 2nd at 4400 rpm, 3rd pulls hard up to 75 mph,
4th buries the speedo and I have no urge to find out how fast 5th will go...Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'sSteve G wrote:
With my header and carb setup I've had NO problems keeping up with 4.0L's. I still have an HEI that I will install.
Yes, it's as good as it sounds.
You might need to change the manifolds, but I'm not sure. If your 258 is an old one, like mine, it would be stupid to put on a 4.0 head and NOT change both manifolds. My motor had the old style manifolds that had 6 into 1 collectors, these are very inefficient. You want the intake manifold that has a large block under the carb/throttle body with long tubes running to each intake port; the long tube that runs the length of the motor with short tubes to the various intake ports doesn't work nearly as well. The exhaust manifold has the same breathing problems and the intake manifold, but going the other way; you want change from the 6 into 1 manifold to one that is 6 into 2 into 1, or some variation that makes tubes that can hold the entire contents of the cylinders before coming to a restriction.
The 4.0 head doesn't have to be fuel injected, but if you use fuel injection or a carb is important when selecting the intake manifold to use.
Before you bolt the 4.0 head down, you need to look at how the water galleys line up between the head and the block. There are (I think) two water galleys on the head that are exposed to the outside, and these need to be blocked off with JB Weld, or something like that. This is an easy job, and should NOT cause you to pass on doing the upgrade.
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