Possibly.Post 13 in my link.

 

Ok so I found out that it is the orrignal engine in it from 1989, that means that it has 297k on it...

 

And this means??????????????

 

It means his motor is all used up...no more go left lol

 

Guess it's time for a new Jeep then

 

That's a short-lived 4.0.............

 

True haha

 

Whatever the problem is/was... it finally failed. I ended up buying another jeep for parts and to rebuild the engine then swap it in, but I still need this one to work for now. Once I got the parts jeep (it ran perfectly so I know that all electrical was good) I swapped over a bunch of sensors and made sure that all vacuum lines were good (IAT, IAC, coil. Plug wires, distributor and other things for testing purposes) I set the engine to TDC and set the new dist in, turns out that I messed up somewhere and ended up blowing the muffler to pieces from a backfire (the concussion was massive ) fixed the distributor to rest at 5 o'clock when engine is at TDC and it ran for a few hours, it was really smooth, but had about as much power as if it were a lawnmower engine (I had to floor it to get it do go anywhere), it got progressively worse until it stalled a couple times and refuses to start, I replaced the cps and made sure that it's getting spark, I also replaced the fuel sending unit and made sure its getting enough fuel, when it was running I checked it with a timing light and at idle it was about 15 degrees advanced - same as my friend running jeep, its also getting good compression about 150 on all cylinders (except #2 which gets 175) so its not spark, fuel or compression, the dist is set to what the manual says. I am stumped with this, so I was hoping someone could shed some light on this (any sensors or anything I can/already have swapped over to try and eliminate things.

Thanks for all the help, even if I can't get this engine running- I have deffinetly learned a lot about this system

 

I found the problem! turns out, the coolant temp sensor wire had a bare section and was grounding to the intake manifold, I guess the computer got a weird reading from it and decided to prevent the engine from starting.

However an old problem still exists.

on a COLD start, the engine will idle fine, but if you try and accelerate it will bog down and backfire, like its getting waaaay too much fuel and lasts until its warmed up. I swapped pretty much every sensor from a known good running 90 xj and the problem still happens, so its either something in the wiring harness or something mechanical. its not the MAP, as running it with unplugged is just about impossible, and its got a good vacuum line, what else could cause it to run really good at idle, but bog down and with enough gas to almost kill it if I accelerate?
something is causing the ECM to send so much fuel that it almost kills until its warmed up.

any ideas?

 

Anything ever been done to the throttle body and IAC?

http://www.jeepforum.com/forum/f9/cl...mmies-1114849/

 

Throttle body has been cleaned and IAC replaced

 

I swapped the fuel rail and all the injectors, and it fixed the problem with #2 cylinder. Also, when I bought a new ICM, they must have given me one for the wrong year it was ever so slightly different on the bottom, I swapped it out and it starts and runs perfectly now, the thing probably runs better then it has in a year and a half! anyway, thanks for the help.

I am really going to have to get used to have 80 more HP, I squeal my tires on just about every corner XD

 

it was the fact that the tach was jumping all over the place when it would bog down that made me think ICM, turns out, I was right.