okay! im looking at a 89 cherokee limited w/inline 4.0 - 6 cylinder. and automatic tranny for trade but wanna fix the problem before i do the trade. the problem is intermittent. sometimes it will start up no problem. then some times it will crank and not fire. however it does not crank propperly. it acts as if the timing is off or something making a retarded noise trying to crank. i noticed the distributor is non adjustable... is there a sensor that controls this? Any help at all would be greatly appreciated! thank you soo much! *Jesse

 

Here is a few things that it could be.
1. cps
2. ingnition control module under coil
3. coil
4. Is out of time,from what you have described it sounds like it is out of time.

 

cps being camshaft position sensor? in the distributor itself? if it was out of time how could it start at times and have no problems idling and running periodically?

 

It is an 89 so it does not have a camshaft position sensor,the cps is the crankshaft position sensor on the bell housing. I mention it because it can act like this before they go out completly,but from your descrption it sounds like it is out of time,that is what I would check first,Put it at tdc and make sure the rotor is pointing aT #1 on the cap.
I would make sure the compression is good before I worry about anything else,make sure the motor is healthy,the rest can be corrected fairly easy.

 

CPS= crank position sensor. It could be possible for it to get a bad reading sometimes and not others or it cold just be bad wiring going to it. the other things mentioned by abovetimberline are also possible and would most likeley have to do with how long its running, such as if it only does it when the engine is warm it could be the coil or control module going bad. The only way for the timing to be off is if the timing cain is worn. I have also seen the keyway on the crank or cam break and alow the timing gears to slipp wich is rare but possible.

 

forgive my ignorance. what is tdc? and the owner said he replaced the crankshaft position sensor. if it had compression problems would it still run healthy? when it runs it sounds great. just periodically it does this, sluggish off timing cranking. ill give it a rest and it has no problem starting. i was told you cant adjust the timing on this motor. that it is a set timing and is controlled with a sensor.

 

tdc mean top dead center,you said it runs good when it does,if it had low compression it would not run good but it would run. I suggest it because it is the first thing I do when buying a car.
If the cps is new then I would look at the icm or coil,even the cap and rotor.
Have you checked the fuel pressure?

 

no i havent checked fuel pressure. dont think fuel pressure is the issue. it does run like a dawg when its cold. was told prolly needed a o2 sensor. when its warm it runs like a champ. so how much am i looking at as far as coil, etc...

 

crank sensor, coil, computer (if u have done any welding and didnt unhook it more than likly u burnt it up...

 

This sounds stupid but does it have a alarm? The reason i ask is i just bought a 91 xj yesterday and today i was messing around with it and locked the doors and went inside i went back out a few hours later and opened the door and tried to start it and it would crank and almost start. I was lick oh great i bought a piece of crap. I then went around to the passenger door and it was locked so i used the key on it. got in and put the key in and cranked it and it started!!! Called the P.O and he told me he forgot that it had an alarm and the only to start the car if you use just the key to open the door it wont start, for some reason you have to put the key in the passenger door and then it will start. just worth a shot.

 

no thats not it. had that problem on a grand am. that was something i tried first. i was pissed off for days untill i read a forum on my pontiac. and was like how the hell was i suppose to know that? im thinkin its a pick up coil in the distributor. if the icm or distributor itself that was bad it wouldnt start at all. it does start and run doesnt die or sputter. if its cold it will sputter. but warm not a problem at all.

 

an 89 has a crank sensor AND a cam sensor. the uses inputs from both to determine timing. you are correct that timing is NOT adjustable. the crank sensor is on the bell housing and the cam sensor is in the "distributor". crank sensor are known to quick working when they get hot and work again after they cool down. the cam sensor will usually just quit. another thing you need to look at is the coolant temp sensor. there are two on a renix cherokee. one on the head for the gauge and one in the block for the computer. you say it starts fine warm but not so well cold? it could be that the computer doesn't know the temp of the engine. if it thinks its warm it may not be injecting enough fuel for the engine to run. time to get a volt meter and start checking things when its acting up.

zedpapa

 

Also, it can be the icm if it is getting hot. It will be fine until it gets too hot, then that is when it will malfunction... if that is the case. Wouldnt hurt to check the cam sensor in my opinion. They are like $40 so its not too bad

 

Oddly enough, I had a 93 that had a similar issue. It would start and run fine, usually on a cold start. But would just crank at other times. Tried a crank sensor with no results. Eventually it happened were I could use a fuel pressure gauge and it was reading zero. The fuel pump was failing...

Hope this helps!