I am out of ideas and cant figure this one out. I believe my jeep doesn't have a thermostat so it take it a long time to warm up to 210ish. But when it idles for a long time and gets to just under 210 it starts running really rough. When I give it gas it smooths out above 2500 rpm and will go away after revving it for a minute. Oh and NO check engine light.

I have replaced tons of parts which are listed below. They have helped but they haven't cured the problem. I will gladly replace a part again if someone thinks its the problem. I am guessing it is heat related. I hooked up the e-fan switch and it is the only way I can keep it from running rough when idling.

plugs & wires 10k miles ago (im thinking of doing these again)
cap, rotor, distributor (last month)
map sensor (last month)
o2 sensor (first one only 3 months ago)
coil (last month)
tps (10k miles ago)
ecu (one month ago, old one was fried)
crank sensor (2 months ago)

My jeep has 180k miles on it so shotgunning parts doesn't really bother me. I might have forgot some but if you have any suggestions please please help me lol. It drives me crazy that I can't idle long off roading without it misfiring or running rough.

 

I had a rough warm idle last week, after all the other parts i changed the Idle Air Control Valve was bad, and the chamber on the throttle body was dirty. cleaning both might help.

 

I will pick one up and clean the port on the throttle body. Wouldn't hurt even if it doesn't fix it.

 

Theyre sixty bucks, I got one from a junkyard for ten that was almost new. Cleaning it first is probably a good idea, I did the whole throttle body. Made all the difference in the world

 

OK cool. I won't have time until Wednesday. I don't think that will help my truck running rough but it will for sure help the idle

 

theres one of these thread once or twice a week. my jeep did the same thing. idle fine until it got warm and it started running rough to the point where it eventually died. i cleaned my idle air control and it didnt help. i cleaned some engine grounds and the battery terminals real well and it fixed it. its been running fine ever since.

 

My battery terminals are new and the battery is also. I cleaned the grounds on the side of the block (passenger side) and re-did a couple of the connectors. I could clean the one from the valve cover to the firewall...its covered in oil/mud hahaha. What other grounds are there?


Thanks for the replies

 

check out this link.
http://www.lunghd.com/Tech_Articles/...und_straps.htm

 

I'll re-check those grounds I re-did on the side of the block (by the oil dipstick). Also I'll clean up the strap ground on the back of the valve cover.

 

its worth a shot. make sure the new terminals are on there really well. it will only cost you your time.

edit: goodluck

 

I even put on some gold plated terminals I had laying around. I'll re-do them for the heck of it. Worth a try

 

Check to see if your intake manifold bolts are loose.

 

Would that throw a code? I'll check the bolts this week.

 

Probably not. Just check them.

 

OK so I put new plug wires and new plugs on it. Also checked the grounds and the intake bolts. Oh and cleaned the throttle body until it was good enough to eat off.

So I'm left with very few options. I'm thinking.
-Injectors
-TPS
-CPS

Any ideas? Please this is driving me crazy!