I have a 94 yj with a 4.0L and that motor went bad so I aquired a 4.0L out of an 88 Cherokee. We had to swap a few parts over from my bad motor mainly timing chain cover, intake manifold, valve cover, fuel rail with injectors, and headers. We put it all together dropped it in no problem. When we started it after retiming it ran for 10 seconds spuddered and stalled. We have double checked the timing including through the distributor at least 100 times it is all where it should be. Now we have flames shooting up from the intake manifold. All grounds have been checked we just put new cap rotor plugs and wires on today and retimed it again. Does anybody have any clue what's going wrong.
didn't the '88 4.0's use Renix injection? I thought the injectors were different.
They are..... Your 94 4.0 was a high output, and you just replaced it with an 88 renix..... The 4.0 HO used the mopar injection. The cylinder head was also improved by mopar to accommodate their new injection system
1989 Base YJ, 4.2l, Borla exhaust, offy intake, Motorcraft 2150 carb, CRT HEI ignition, ax15, np231 JB conversions SYE, D30 ARB & Ford 8.8 ARB 4.56, 35x12.5r15 Goodyear MTR's, bds 3.5" springs, 1" body lift, and 1/2" Boom Shackles.
Build Thread: http://www.wranglerforum.com/f330/fi...ld-385106.html
The injector problem is fixed its all getting fuel. My mechanic friend says its all in the timing and distributor but it was set up as the Haynes manual and forums say to do it. Could it be because we used the distributor from the 94 motor it looks exactly the same as the original. Also many of the vacuum lines arnt connected because they are bad and waiting to be replaced. But it should still start from what ive been told. Any ideas? Thanks for the help