jason96r

I have a 1989 Cherokee with a 4.0L and an AW4.


Sometimes after starting my Jeep it will act like it wants to stall but doesn't. I mean it will be running and then the idle will drop down around 200 RPM and almost stall and sometimes it will run fine and then start doing the same thing once I put it into gear. Now it does not do this everytime and I have replaced the IAS previously and have cleaned out the throttle body not long ago so I'm not sure what this could be. Though it has stopped doing this a week or so ago I am confused by this as it seems that it could be a IAS problem but that has been replaced months ago for a seperate idle issue, which it fixed.

Also, about 1.5 months ago I was having issues with my Jeep not starting. Now it would start eventually but it would take awhile. Now I would try to start it during this time as if the NSS was bad but that wouldn't change anything and when it would not start I checked and had no spark. I checked and thought it was a CPS and I did get one but while it was on order I decided to clean all of the connections on the coil, TPS, IAS, and CPS and have not had a problem since.

Now I mentioned the second thing wondering if my latest issue could be related and if I should go ahead and replace the CPS with the new one?

azxj99

i had a similar problem... i thought it was bad gas so i filled it up and it didnt help.. then i put a bottle of fuel system cleaner in it and it hasnt happened since... i try to stay away from the crap gas and buy shell or cheveron... good luck
david

RENIXBEAST

x2, my 89 does the exact same thing. I run mid grade or plus and it runs way smoother.

jason96r

Thanks I didn't think about that I let my dad borrow the Jeep for a day or two and he put a tank in it, but I can't remember if it matches the timeframe, and he usually buys the cheapest gas possible. I usually buy the midgrade stuff from either the Marathon near work or Shell near home.

Thanks for the quick response I completely ruled out anything fuel since I was getting fuel, have replaced the fuel pump and filter, have ran plenty of fuel cleaner and seafoam, and have cleaned the fuel injectors and throttle body. I don't buy the cheapest gas possible but since I'm not sure what my dad put in the tank and he usually goes for cheaper stuff I guess that could have been the issue.

azxj99

let us know... you may want to run another bottle of fuel cleaner just incase not going to brake the bank and does no harm

jason96r

Yeah I kind of forget how crappy gas is now a days. Well with my other car I'm very picky about gas as it has a high performance high compression engine but the old Jeep I will throw anything in haha. Actually, I had issues with it a while back and a mechanic friend said put some better gas in it so I have been. I think gas may have been the issue as I haven't had an issue with it for weeks and really I posted this just because I happened to be on this site. I remember now that when my dad borrowed it he said he filled it up which I was greatful for cause he only went like 5 miles round trip and filled the entire tank but maybe he did get the cheap stuff.

Anyway I will keep you guys updated.

I'm really doing some work on it as I have money hoping that it will have no down time this winter. Though I've only had it since December have really gone through it. Since I've already bought the CPS for it I will throw that on it and after that I will only not have replaced the TPS and the coolant sensor LOL.