Hey guys spent the past 4 days trying to troubleshoot this problem with no success. Jeep started in morning then turned it off to work on new stereo I'm putting in. In the process of re-wiring the new stereo I shorted out the Pink and Red/White wires which proceeded to kill my dome lights, cigarette lighter etc. Replaced that fuse, lights come on all seems fine go to start the car and now have no spark. I have traced the problem back to no power coming into the coil. Replaced CPS, checked grounds, checked throttle position sensor, checked power at computer plugs, everything seems inline except no power to coil. So wondering if anyone has some ideas of items to check?

 

What year? Could most likely be a fusible link. Did you check everything in the power distribution center and the kick panel inside? I shorted a wire in the headliner with the same results but I replaced the blown fuses and was good to go luckily.

 

'97 and yeah i have checked every single fuse under the hood and by the passengers feet, also have swapped all relays so i know all relays are good.

 

I used to have a diagram with location of all the fusible links but I can't find it at the moment on my phone. Maybe someone can chime in with it before I find it.

 

I made a thread a while ago, but instead of bumping, I'll ask my question here.

My 96 cherokee has some trouble. when im driving, sometimes (it happens mostly when it's very cold outside) the cherokee will have trouble giving proper gas. even if I put the pedal to the floor, you can see the rpm go up and down, like if it was stopping giving it gas, and then giving some again. if I put it in 2nd or 3rd gear and make it rev alot, at one point the issue will stop but will start again 10 minutes later or when I restart the car.

no check engine light, no error codes. so I bring it to the garage and the guy told me he found out I needed a new o2 sensor.

so I was wondering, could this problem be caused by a faulty/old o2 sensor or is there something else? (we thought maybe a clogged cat or something like that, but I don't know if the guy checked that)

thanks!

 

Sounds like it could be your Coolant Temperature Sensor. Try unplugging that. If it drives normally with the CTS unplugged, replace it. May not be the problem, but it's a free test.

 

Perfect, thanks!

But the car is already in the garage and the guy is awaiting my word if I get the sensor changed or not. I guess I should still do that?

 

Ok so I was geting symptoms of haveing a bad NSS, for the last day are so, but on my ride home from work it seemed like to clear up. So I want for a nother lil run around my block once I let my jeep cool back down sence that's when symptoms are at the worst. Well about 2 min into driving it the brakes got hard brake lights came on than my jeep died. Now it doesn't start at all nothing. Checked all my fuses, taped my starter, did what I knew first to check for well I've got nothing.??? Anyone has a suggestion are can a bad NSS cause this to happen?

 

A bad NSS will not kill the engine.

You don't have driveability issues with a bad NSS.

A bad NSS will cause a No Crank situation and no reverse lights. That is all.

Sounds more like CPS than NSS to me.

 

This^^

 

Does it crank or no? NSS can lead to a no crank, CPS will cause stalls but you'll still crank. As for the brakes sounds like a number of things could've happened.

 

Is there anything linking the power braking system to the lights and the motor?

 

No big surprise that you have a bum O2 sensor... 17 years is a long time. A clogged cat might cause your issue but it would be constantly present. Honestly this sounds like a sensor issue. I'd suggest checking your Throttle Position Sensor, should be done with an analog multimeter. It's got a 5V feed going into it, the idea is that the output from a shut throttle to wide open should be a smooth sweep from ~0VDC to ~4.5VDC. There are a few writeups on here with more detailed steps if you prefer. The TPS is used by the ECU/PCM for fuel mapping, setting idle RPM, and telling the transmission when to shift.

 

Lights?

Power brakes are vacuum boosted off the manifold, so if vacuum was lost they'd firm up after the reserve was depleted but I'm not sure if the brake light would illuminate... but if the booster hose came off you'd have a nice vacuum leak too, should send the RPM up a tad.

Isn't a loss of pressure in the lines what sets the brake light off?

 

I meant brake lights. I really don't know, I was just asking the obvious question.