Bad Idle

[TheFallenJosh]

Ok well my non turbo with an automatic trans is my DD most of the time and it has 200k miles on it. It has had this problem for awhile, but it seemed a lot worse today. When I'm at a stoplight the car starts to shake when idling and the RPMs drop to about 800 or so, sometimes a lot lower. It shakes pretty bad, but not horribly. Now also to fix this I usually put it into neutral to stop it. I did that today and I got idle surge, it would go back and froth from 1500 and 1000. Now it only idle surges when it rains (which really baffles me). The car also has a number of CEL codes. I fixed a few of them but haven't cleared them yet. I'm probably going to have a diagnostic run on it at some point, but for the time being does anyone have any idea on what it could be? I believe its a faulty sensor of some sort that is getting wet.

 

[cliffkemp]

check your egr valve...also check your tb hoses for leaks...I had a neon do this for similar reasons...also, do you have any other symptoms? only when hot or something else to go by?

Check out your TPS as well. it may be going bad...

 

[95TalonOwner]

Take off your egr and iacv and clean them to make sure they are sealing correctly.

 

[TheFallenJosh]

Thats really all the symptoms I got, everything else is pretty much ok. I fixed a lot of the issues regarding the CEL codes awhile back. Thank you for the help guys. Also, I had the temp gauge say the car was getting hot back in the early fall every once in awhile, but I'd get out and check and it would be fine. Is that a faulty thermostat issue? I'll try your suggestions and see where I am.

 

[cliffkemp]

have you checked you oil lately to see if you may have some coolant in it...thermostat issue can cause poor running conditions and may cause bad idle...A map sensor that is going bad can do the same thing. electrical problems are tricky, if that is the issue....check all your sensors and the egr operation as well...it is possible you may have bad gas as well....electrical issues are a pain and sporratic until something actually quits....its a game of elimination 90% of the time....is there any smoke coming from the bay or exhaust???

 

[Blu92]

I had that idle surge on my 1G. Pulled off the EGR and cleaned all the carbon buildup out of it and that fixed the problem.

 

[renovatdkitchen]

I'd say replace the TB gaskets and check/replace the vacuum lines. Most likely a vacuum issue. Unless, do you have an exhaust leak? Might be that or a ba o2 sensor. But that's just my idea's.

 

[cpoindexter]

Check for vacuum leaks. My roommate's 420a would idle rough and it has gone away after the timing belt and tensioner were replaced and has yet to come back(knocks on wood).

 

[TheFallenJosh]

No smoke, no vacuum leaks, not a bad 02 sensor (I just replaced it like 3 months ago, because I knew it was broken the car barely moved) Its not an exhaust leak either no coolant in the oil either, I have to check the oil everyday anyway since its got a leak. I'm just gonna take off the EGR valve and clean up the throttle body and IAC. Thanks guys, I'll update when I've done it to see if it worked.

 

[Abe'sGST]

do clean up the egr and all previously said...you dont have a misfire do you?

 

[cpoindexter]

Would you by chance have a wideband hooked up? maybe too rich?

 

[TheFallenJosh]

do clean up the egr and all previously said...you dont have a misfire do you?

I had a CEL for a misfire, but I'm not sure if I still have one or not.