93 cherokee won't start (not normal)

[Dustin075]

I have been looking around on this site for the past few days and I can't seem to find the answer to my question. So here it goes, got a 93 Cherokee, 4.0, manual tran, four wheel drive. I have had a no start/ starts when it wants to problem. I have replaced the coil, plugs, wires, cap/rotor, and o2 sensor. Thought I was good when I did this, took it out on the trail ran good for about 15 mins then started to back fire out of the intake, and just running like crap no power at all. Shut it down go to restart it and it will just crank. If I let it sit for a day it will start and run for 30 seconds then die, then not start again. I am so lost I what to do. Please help.

[bigjim350]

Sounds like you may need to change the CPS (crank position sensor) Have you checked to see if its getting fuel and/or spark while your trying to crank it, and it won't start?

[Mudderoy]

I have been looking around on this site for the past few days and I can't seem to find the answer to my question. So here it goes, got a 93 Cherokee, 4.0, manual tran, four wheel drive. I have had a no start/ starts when it wants to problem. I have replaced the coil, plugs, wires, cap/rotor, and o2 sensor. Thought I was good when I did this, took it out on the trail ran good for about 15 mins then started to back fire out of the intake, and just running like crap no power at all. Shut it down go to restart it and it will just crank. If I let it sit for a day it will start and run for 30 seconds then die, then not start again. I am so lost I what to do. Please help.


Sounds like you may need to change the CPS (crank position sensor) Have you checked to see if its getting fuel and/or spark while your trying to crank it, and it won't start?

Yeah the CPS is a very common issue. Make sure the connection is good first. Just unplug and replug. It's the connector to a pair of wires that go down behind the engine on the driver's side of the bell housing. Behind the throttle body on the intake side.

[Dustin075]

I thought about replacing that, but wouldn't it just go out and not work some of the time...? I "heard" when they start to go out it senses that the motor is off a 180 degrees. I mean that would make sense now I think about it, with it back firing through the intake and all.

[xj4life2]

CPS can be intermitant and do exactly whats happining to you. They also can test fine and still not work. I would change it and see what happens I'll bet you fix it. You could also try to just unplug it (at the connector on top of the manifold) and (it sounds strange) blow it out and re connect it. Chances are it will start I went a couple years doing it this way so I know it works. With all the issues we see here on Jeeps , if it comes in with a no start we change the CPS first and eliminate that issue. I also carry a spare with me at all times and have eliminated the plug in and hard wired mine. The plug can cause voltage loss and cause the issue your haveing also.

[bigjim350]

The last time I replaced one, it was going bad for a while. Sometimes they just quit sometimes they don't

[Dustin075]

Well there 60 bucks at a zone, so I'll throw one at it and see what happens. Need to have it ready for Sunday to wheel with a few buddies. Thanks for all the help guys. I'll report back and let you all know what happens.

[Mudderoy]

Well there 60 bucks at a zone, so I'll throw one at it and see what happens. Need to have it ready for Sunday to wheel with a few buddies. Thanks for all the help guys. I'll report back and let you all know what happens.

Yeah please let us know the solution. :drinking:

[Dustin075]

Ok I replaced the tps and nothing. Getting fuel and spark. Any other input..?

[Dustin075]

I can't delete my other post, so it will start and run on idol. When you give it gas it back fires though the intake still. It will idol for a bit then die, and won't start again for a bit. I am so lost, I am about to scrap the thing.

[4x4Dalton]

Check all yer fuel injectors and fuel filter. Sounds like there might be some trash in there.

[Dustin075]

Got it fixed! It was the CPS, and the coil I had just replaced. Not sure if the bad CPS had made the new coil crap out or what.

[LizardRunner]

brand new coils can crap on their own. I've had it happen on several parts you wouldn't think about this as a problem normally. Like going through five starters once to get one that stayed alive.