[Guest]

Hi, My son has 1990 Jeep Wrangler with a 1995 engine in it. Lately he has been having problems with it. It starts running rough and then quits. At times it seems like it isn't running on all cylinders. I'm not sure what moter it is. Any way he was looking for a diagnostic link, but can't seem to find it. Can someone tell me where it is? Also since it is a 1990 chassis with a 1995 motor do you think that the computer in it is a bit confused or something. He has had the Jeep for about 4 months but this is something that just started. Sorry to be so vague about things. Would the diaganostic link be the same as say a 1990 Ford so we could use the same code reader? In my 1985 Camero all you needed to do was jumper 2 of the pins and the check engine light would flash error codes. I don't imagine that this Wrangler has the same thing....does it? Thanks in advance for your help...Tim

 

[Tippy]

Search this bbs for diagnostic codes. Its been posted lots of time in the past or go to Jaffer's web site. He has the codes listed there. If you turn the key on and off in a certain sequence, the check engine light will flash telling you in a pattern of bleeps what is wrong.

 

[959]

is the motor a 6 cylinder or a 4 cylinder?
Was it originally 6 cylinder or a 4 cylinder?

is it fuel injected?
I hope that it is a 4.0L straight 6 motor with MPI fuel injection, which is very common to jeeps.

 

[Guest]

Ok I have a little more info. It is a 4 cyl 2.5 liter engine with trottle body injection. What it basically does is afetr you start it up it runs for about 1 minute then starts to misfire then stalls. If you give it the gas it will run but rough. Sounds like it isn't getting any gas but I can see gas squirting in the trottlebody. We hooked up a timing light, it seems to be set at 8 BTDC. Is that adjustable? I did notice alot of soot in the tailpipe. Also I looked at the dash there doesn't seem to be any check engine light. I thought at first it was just blown but I looked with a flashlight and there is no check check engine light.

 

[1238]

Throttle position sensor perhaps.

Here's why I say that:
If the TPS is faulty then it may be sending errant information to the ECM and causes it to dump too much fuel into the engine causing it to run rich and produce all the soot in the exhaust.
Of course, it would also effect other things which may all be contributing to the problems you're experiencing.

 

[959]

I thought all the 2.5s where MPI? how can it have a TBI? do you have a camera? post some pictures?