PDA

View Full Version : rough idle and misfires after jeep warms up



toast018
02-22-2010, 01:17 PM
So last night I had to pick my brother up off the side of the road. He called telling me his Jeep just started running really rough. I drive to see if I can fix it there on the road side. When I get there he starts it up and let's me hear it... its running really rough, misfiring, etc. I assume water in the gas, since they just filled up. I go and get a bottle of heat in the red bottle.

Pour it in and try it again... Still no better... so I tell him to drive back to his house while I follow since its not but 3 miles from where we were. We make it to within less a half mile when it gets real bad. I unplug the tps then the iac and then the maf just to see if it would help (found the problem on a friends impala by doing that) still running like poo. So I take them home and they get a friend to tow the truck sincee my lil hyundia wasn't up tp the task. I txt him first thing this morning and get him to start the truck. He calls and says it started fine and is idling fine...

So I'm thinking its the coil causeing all the fuss... what about you guys?
I also think it may be the temp sensor that tells the ecu what the temp is and when the engine warms up the ecu is getting a bad reading and causing all the problems...

Could the TPS also cause this?

pvt.Tadpol xj
02-22-2010, 02:02 PM
I would say the Ign. Coil..Maybe fuel filter. If you have to try replacing some part's start with the least expensive one.The fuel filter. Are you getting any on-board code's?

cheap jeep
02-22-2010, 02:04 PM
I would guess that it's the coil, I don,t about the tps,when my tps went bad the trans wouldn't upshift but the engine ran o.k.

toast018
02-22-2010, 04:05 PM
I would say the Ign. Coil..Maybe fuel filter. If you have to try replacing some part's start with the least expensive one.The fuel filter. Are you getting any on-board code's?

I never thought of the fuel filter. But I wouldnt think the engine temp would effect it?

Mudderoy
02-22-2010, 04:50 PM
I never thought of the fuel filter. But I wouldnt think the engine temp would effect it?

DON'T TRY THIS AT HOME!

I had a 1982 Z28 that starting having problems with high RPMS then it just kept getting worse. I got a long pipe and punched a hole through the catalytic converter, problem solved. :shocker:

alwaysxj
02-22-2010, 08:30 PM
could of just been the vaccume hose when you took it off and put it back one it stoped leaking.

toast018
02-23-2010, 07:56 AM
Forgot to mention no codes are being thrown... :)

pvt.Tadpol xj
02-23-2010, 08:05 AM
I have to say last summer i had a little trouble with my temp sensor and it threw a code every-time i cranked her up, and the electric fan would stay on all the time. I believe it's something simple what-ever it is....:smiley-laughing021:

90jeepxj
02-25-2010, 08:02 PM
I am having the same issue i am gonna work on it this weekend and if i fix it i will post it

wv jeeper
02-26-2010, 10:33 AM
It could be the coil pack but probably is'nt. My 2000 did this and i changed the coil pack and tried a new ECU. Neither solved the issue so I ended up taking off my fuel rail and pulling the injectors. Turned out my fuel rail was so full of crud # 5 and 6 cylinders couldnt get fuel. Cleaned everything out and everything was good.