I’m at a complete loss here, I had a problem with my 1999 jeep cherokee classic where it wouldn’t start this week. it has fuel pressure, and injectors are delivering fuel. the spark is a yellow/orange color which means it’s weak. correct? so I installed a new coil and it started up, but barely. It would start and would continually try to stall out at idle, so i went on and replaced the distributor and spark plugs and now won’t fire what so ever. Did I install the distributor wrong? I was pretty confident that i had the timing set properly. Or is there something else i’m missing here? Is it possible it’s a bad pcm?

 

Welcome to the forum.


Correct.



Probably. Never assume. Double check yourself, and do NOT use any info that comes from Chilton or Haynes. They are often wrong.


Yes, it's theoretically possible, but that's a long way down the list of possibles.

Check the basics: How are your cables? Grounds? A bad ground here and there can wreak havoc on many systems. This is especially true with our XJs because most of the engine functions get constant 12v, and then the PCM provides ground to fire the device (coil, injectors, etc.). A marginal PCM ground will cause lots of grief.

The PCM grounds to a plate near the distributor, and your main battery cable grounds there, too.

 

I checked the grounds and they seemed good, is it possible that a bad CPS would cause a weak spark?

 

Update: Replaced the CPS and checked the grounds, still nothing. I do have power getting to the coil, had 11.5 volts and the battery was at 12.06V. So I did new spark plug wires and tried another new coil. Nothing did the trick, still cranks with no fire, even with starting fluid so i know it’s not a fuel issue.

 

CPS won't give a weak spark.

How did you check your grounds? IF you didn't take them apart, you didn't check them.

 

Error codes?

 

no codes

 

i took them apart. i did the ones right under the coil mounting on the block. are there any more i should be checking?

 

CkPS issues can be present without generating error codes.

The distributor was complete, including camshaft sensor?

Handy with a multimeter?

 

yes the distributor was complete with cam sensor, i replaced the crank position sensor too and didn’t make a difference. And yes I can use a multimeter.

 

If the grounds are good and clean the new CPS didn't fix it, then I'd have to say its the part that provides the voltage for the spark. Battery or alternator? If you have a battery charger, hook that up and see if it helps to start the engine, or just an old school jump start from another vehicle. If it starts up much easier, check your battery and alternator cables for signs of bad stuff, loose connections, etc....

 

tried a jump start and a new alternator too

 

Dang......

 

maybe they gave me a bad alternator? i got a remanufactured one from advance. it was making a pretty loud whining noise after i put it in but the bearings feel fine.

 

Possible. Odds arent great, but its possible. I want to say that the distributor cap CAN go on wrong, but if it had this issue before you replaced that, its probably not the issue, unless it had moved by itself before you replaced it and put the new one on in the same orientation as you took it off.

Did you replace the rotor with the cap?