Jerry Forrester

Thanks hornbrod, I will check that out Monday. I switched the ASD and fuel pump relays today. Nothing changed. won't run.

First, let me thank you for reading all the posts instead of just reading the last one and posing a solution that has been addressed several times already. Correct Correct. Correct and I have NOT replaced ANY wires. I will admit that I have not checked all the grounds. This Comanche has spent it's entire life in Georgia. We don't have the problem with corrosion here as much as some of the states which use salt on the roads. Notice I didn't say we have NO corrosion, just not as much. I'll check the grounds Monday. Thanks Scott, I'll get back to barking at it Monday and see if I can tree this coon. Jerry

Thanks hornbrod, I will check that out Monday.

Today I installed the NEW new CPS. won't run. Still getting a weak spark out of #4 dist. terminal and a weak double spark out of #1 dist. terminal. Help! Jerry

It's a '91 4.0 High Output. 5 speed. When it first quit running, I put in a new CPS. won't run. Then I put in a remanufactured distributor. won't run. Then I returned that dist and got a new distributor. won't run. Jerry

Thanks for the diagram and the pic. There doesn't look like there's anything with the flywheel that can cause this problem. Is there an ASD on my '91 4.0? How do I find it and how do I check it? I checked the codes by turning the ign. switch on three times and got an eleven and a fifty four. That's the CSS and CPS. I have replaced both of those with new items. I then disconnected the battery for ten minutes to erased the codes. Now all I get when I check the codes is the code twelve that starts the sequence and code fifty five to end the sequence. That reference gave me a picture of a CPS connection with three straight across pins. My '91 4.0 has three pins arranged in a triangular pattern with no A-B-or C on the connector. Thanks, Jerry

I agree about the two stage compressor. It's the only way to go.

Oh yeah, I have checked the compression. Ranges from 110 to 125 lbs. Not ideal, but probably what one would expect from a 257,000 mile 4.0. I also have the valve cover off to check the movement of the rockers. Everything there looks good. I have never seen a Jeep flywheel that triggers a CPS. What does it look like? Is there something there that could be causing this problem? I'm grasping at straws here now. Jerry

When I borrowed the noid light from my buddy, I checked only one injector's pulse and it had pulse. I borrowed it again and checked all the injector feeds. Got pulse on 2,3 and 6. Nothing on 1,4 and 5. Hooked the remote starter button up so I won't have to rely on someone else's interpretation of what is happening under the hood while I am cranking the engine over. At this point in time, I have the plugs out and the cap and rotor off. I spin the engine and check the spark coming out of the coil wire. I get two sparks (yellow), then a long pause, then two sparks, then a long pause. In other words, it's firing only two times per distributor revolution. I reinstall the cap and rotor and check the spark coming out of the distributor cap. I'm getting spark (yellow) out of terminals four and one. The funny (as if anything about this could be construed as funny) part is, the spark from number one terminal is a double spark and the spark from the number four terminal is a single spark. I have tried both ECM's and am getting the same exact results from both of them. So what we have now is, No pulse for injectors 1, 4, and 5. No spark for plugs 5, 3, 6, and 2. Weak yellow spark for plugs 1 and 4. I'm going back to the beginning. The CPS. The Haynes manual says to check continuity between terminal A and B on the CPS plug, if it is bad it will be closed. There are three pins in the CPS plug and NO A or B. But there is no continuity between any of the three pins. That is supposed to mean the CPS is good. (Remember, this is at the start of this fiasco.) I bought a new CPS and installed it. Wouldn't run. A couple of days ago I checked the 'new' CPS I had installed. It shows continuity between two of the three terminals. Does that mean I have a bad 'new' CPS? Yesterday I traded that 'new' CPS for another new CPS. That's as far as I have gotten so far. I'll have more to report later. Thanks for all the help. And please keep it coming. Jerry

The battery is strong, less than a year old. But of course with all this cranking and no running it was getting a little low. But I have a good charger with the boost feature so that's no problem. I have narrowed it down to electrics, it's not a fuel problem. I have all the plugs out of it now to releave the stress all the cranking was putting on the starter. Don't wanna have to buy a new starter too on top of all the other stuff. thanks Jerry

Thanks, tried it and it still won't run.

Thanks deziped. I'll pick up a can of carb. cleaner on my way to the shop tomorrow morning and try that. I don't think I need to run a compression test because I have a hell-of-a vacuum pull through the throttle body. But because several people have asked me if I ran a compression test, I was going to run one. Got my old military surplus tester out (been using it since the early sixties) and find I don't have the long reach adapter to screw into the spark plug holes. I'll borrow one from my friend tomorrow and do the compression test. I'll let you know the results. Jerry

The used ECU came in today. Had it installed about 15 minutes after the UPS guy left. Still won't run! :mad: :help:

What language is that? Cop talk or something? :nuts: Jerry

Okay, I lied. I wasn't able to let him sit. Several guys around here have told me that they thought I had a bad reman. distributor. I talked my guy at O'Rileys into letting me return the reman. dist. and selling me a new dist. The new dist. comes with a cap and rotor, (I had to buy the cap and rotor for the reman. unit separate), he let me return them too. :banana: I installed the NEW dist. Fri. afternoon. Guess what. won't run! Have any of you guys got an ECM to sell me cheap? Remember, it's a '91 5 speed. There's a used one on the bay right now for $60, free shipping. He claims it came out of a running '91 Comanche. He'll accept returns but I'll have to pay the shipping back to him. Sounds like a good deal. He has almost 4000 sales and a 100% feedback rating, but I would trust a guy on this forum more. BTY, I have almost 1200 sales and a 100% feedback so I know how hard it is to keep a 100% rating. Sometimes you have to do some crazy stuff to make 100% of your customers happy. Jerry