owellwhatever

Ok, this is my 3rd Cherokee and I got it cheap and needing some TLC, as a project for this Spring/Summer.

89 Laredo, 4.0L, AWD auto, stock, 158k, nothing leaks but it had sat for while until the gal started driving it again for a few weeks.

So, it was having a hard time starting, long cranks, then would sometimes die. Other times would start in normal time. Was idling really rough. Had an intake maninfold AND exhaust manifold leak as well.

I replaced the plugs, wires, cap and rotor, IAC and found that pulling vacuum froum the EGR solenoid to the valve helped so I replaced the solenoid and that helped a lot.

I broke two studs trying to pull the manifolds, so I took it up to Olympic 4x4 and had them replace the gasket.

It was then running much better but now sometimes stalls/hesitates when stopped in drive, or when just starting to accelerate. They noticed this on their test drive and threw a used "good" MAP sensor in it and said they adjusted the TPS. But it's still doing it.

I have read about testing/adjusting the TPS and plan to try that myself, but haven't yet. All of this is new to me, including using a multimeter But the first non-rainy day this week (In Seattle), I'll test it out.

I have also read that a bad NSS can cause symptoms like this. It does have a bad NSS, sometimes you have to move the shifter a bunch before the ingnition will work and reverse lights don't work. I cleaned and greased up the NSS on my 93 to fix the same issue, so I will be doing this first this week before checking the TPS.

Well, I want this one to be a learning experience, that's partly why I picked it up, but I also don't want to get in too deep or get too frustrated. So... does it sound like I'm on the right track? Any other suggestions?

owellwhatever

Well I cleaned and regreased the Neutral Safetwy Switch today. I now have reverse lights again and it started every time in Park!

I drove it 5 times today but not too far. Once up and down the freeway as well. I really didn't have any stalling or hesitation issues, but will have to drive it more to be sure. But, it is still idling high, especially when warm. I'll check the TPS next. Anyone think I'm on the right track? Any other suggestions?

Thanks and Cheers.

Derrtydave

Ive been having a problem with my reverse lights not working... At first the problem was intermittent (sometimes they would come on, sometimes not) but for the past 8 months they have been not coming on at all when I throw into Reverse. I'll now try cleaning the NSS as you did and maybe this will fix.

lestatsghost

I hope you can figure this out. I have tried just about everything you have and found tightening the intake and exhaust bolts helped. they are known to shake loose on Renix models but I still get the problem but not as much now. I replaced the TPS and it didn't help. I also cranked on the exhaust/down pipe connection to snug that up and gave the O2 sensor a bit of a turn too. I've also gone through and replaced every vacuum line with new but it still happens. good luck

owellwhatever

Well I drove it a bit more and it still stalls when I first hit the gas. I got the idle down by cleaning the throttle body, and my buddy adjusted the timing when we did that, said it was off. It idles at about 800rpm now, but I still have the stalling issues.

I haven't checked the TPS yet though, only time to do so much at once...

owellwhatever

That's definitely the Neutral Safety Switch. They're around $200 new, and most shops will charge close to $400 to replace. Anyone with even limited mech ability can rebuild one for under $10. I don't have time to post the links at the moment for the tutorials, but start searching and you'll find them. Search Google as well.