View Full Version : Rough Idle

10-21-2003, 06:44 PM
My car started having a rough idle yesterday, it normally idles at about 500-600 rpms and vac is about 16-18" but it's pulling 10" or more sometimes and is idling rough but after a while it smooths out... I tried pulling codes but it doesn't want to scan? it gave me a prom error on the KOEO the memory test said 111... the only thing i've done recently was add an apten chip about a month or so ago but it just started happening... Last night while idling the check engine light flashed three times... I'm thinking IAC, Vac Leak, or Cam sensor... any ideas? btw it was really really rainy yesterday (live in seattle) but my K&N didn't really seem wet. (MAC CAI)

Thanks in advance

10-21-2003, 11:31 PM
Cheapest thing to do is start the car and spray carburetor cleaner at the IC tube connections and vac hoses ,if the idle changes at any of those connections , that will be your leak. IAC would be my second guess, cam sensor failure is usually a hard starting type of problem i think. You could also be experiencing a DIS problem which is hard to get to show up on the vague ignition codes our cars give off. Start simple and work your way in.
Good luck

10-21-2003, 11:58 PM
K I work at a ford dealer in the service dept I'll just have one of the guys hook the smoke machine up and see if we can find a vac leak...

Anyone have any idea what the 3 flashes of the CEL are? it did it again tonight and reved up to 1500 rpms for a a little while.

sho taurus
10-22-2003, 06:27 AM
mine started off that way did it sometimes and then would run fine,but then it got to point it wouldn't idle or have any power... intake bolt came loose and started leaking so i replaced intake gasket also just to be safe.and how i found it was with carb cleaner like mentioned above reply.hope that helps ya

10-22-2003, 05:17 PM
Sorry about the rain Rookie:D
In Vancouver WA here and you all north of us got all the rain. Did i mention a record 80 some degrees and sunny here yesterday?

Kidding aside, have your tech co-worker throw it on the machine. With that 2,000 idle I'd suspect a bad IAC though. Good luck as my bad IAC gave no codes other than O2 sensor reading rich/lean. Replaced O2's and same thing.

10-22-2003, 07:18 PM
I seem to be having a problem with mine to but my idle dose not change much. I hear this whistle sound real faint but its coming from the IAC. Here is my problem. Some have said that by disconnecting the wire the car should try to die but on my car this only happends when its cold. When its hot or at temp it has no affect on the engine at all. I do get 14 volts from the leads but this car starts just fine untill the idle speed starts to slow and it starts to miss or pop untill it reaches normal idle and no more missing but other than that the car runs strong.
This is on my 94 also. anybody have a clue?

10-22-2003, 10:06 PM
sound similar about what mine does... I'll let you know what they find on it... they couldn't get to it today...

10-23-2003, 08:30 AM
Originally posted by scbird1
[B]..........I hear this whistle sound real faint but its coming from the IAC.[]

Sounds like maybe the $2 gasket could be leaking. Try to pinpoint the source of the leak. Maybe the PCV valve connection come loose? Maybe a soapy water solution in a spray bottle may show you your probs easily enough. Also if you HAVE TO replace the gasket, DO NOT try and clean the IAC out or you'll have a bigger problem. Also when reinstalling the IAC with a new gasket, unplug the electrical connector to the #2 injector as it gets in the way of the lower IAC bolt. Put mine in crossthreaded and cracked TB. Ouch! :mad:

IAC Gasket $2
IAC Valve $80 (Don't buy an aftermarket as people have probs with these)