Idle Out of Control (IOC)!

[starla3366]

93 Lumina (VIN T)

Problem ( Persistant 1.5 years)

When I initially start her up, she idles like no tommorow. I have no TACH so I have no idea what RPM she's at. I let the oil pressure build up and then I put it in gear. Funny thing is, I can still feel the motor pulling hard yet it seems quieter/slower. After I get to where I want to go (roughly 20 min drive), and I put it back in park, she seems normal. Then I shut it off. I come back and the idle is back up again. Does not matter if it's cold/hot. I've struggled with this long enough, and searched long and hard, for answers. And this is what I have done:

R/R

spark plugs
O2 sensor
Idle air control valve
air filter
pcv
oil/filter

I am in need of help soon as the Maine winter will take it's toll on this high idle badly.

Please help,
tony

[paulfischer]

I would try to clean out the passage way for the IAC. Where did you get the IAC from? I'm leary of electrical parts from Autozone. I had a IAC come apart on me...... good things I was close to home.
I would also relearn the idle process.

[starla3366]

I cleaned out the entire passageway of the IAC except i did not get into the actual throttle body. I was thinking about doing that but, then i realized how much work it would be and how little time i had. I'm not quite sure the throttle body being dirty is the problem though.

I have searched everywhere for vaccum leaks and only found one. It's the Cruise control vaccum. Has nothing to do with Idleing.

As for where I bought the IAC. I bought it at Advanced Auto Parts. I have never, never, never had any problems with them.

Now, the chiltons does not exlplain anything about the relearn process. Or maybe I overlooked it in my drunken/sleepy daze.

Please explain the re-learn process. I will google it also.

many, many, many, thanks

[cnilkyrclit]

what is the easiest/safest way to the iac passage way. i have recently replaced the iac and lately when i start my car it idles at 2000 rpm's. i pulled the positive cable for the battery to reset everything, so far so good. also when i stop at a light the idling is going up and down for a fews seconds then it levels out(goes up and down between 500 and 1000 rpm's, then levels out just above 500 rpm's). what is a normal rpm range?
93 lumina eurosport sedan 3.1 v6 131,000 miles.

thank you everyone.

[starla3366]

Google is so much fun!

For all who do not know!

Idle Relearning

http://www.xse.com/leres/efidiag/idlelearn.html


I'm going to try this, and see if this solves my problem.

thanks again

[starla3366]

The Idle Re-Learn Trick did not work.

Just last night I did a lot of work to this baby.

I removed the throttle body, the egr, and the upper plenum. For possible vaccum leaks I replaced the throttle body gasket and the two egr gaskets. I also cleaned everything up (from the throttle body all the way into the deep crevices of the plenum), I even painted the upper plenum, to make it look all nice and purrty.

One more think I did was the Throttle body Coolant Bypass.

I reinstalled all of it back with in a hour or two. No problems what so ever. Easy as counting One, Two, Three.

Then........

I reconnected the battery, Turned the key on for ten seconds then back off. Then I started the car. Kind of hesitant at first, but she purred like a kitten. She was Running beutiful. This was about 1 A.M. this morning.

So, I wrapped things up happily. I went to sleep knowing I fixed the problem.

But.........

This morning (6 A.M.) I hopped in, low and behold, she was Idleing high again. I don't know what to think anymore. I got the Check engine light on with the paper clip code of 35.

One thing I regret doing so far is not replacing the Upper plenum gasket (I was short on 35 bucks) and using fuel injection cleaner to find vaccum leaks.

Anyone else have any Ideas?

I need help, pretty badly.

[starla3366]

I'm just a little anxious

[jeffcoslacker]

Did you fix the vacuum leak at the cruise control that you mentioned?

[starla3366]

Yes, the cruise control vaccum leak has been stopped. The tube dried up and broke. Located at the FWD Driver side of the vehicle. Right near the bumper. The tube connects into something that looks like a hollow ball. I don't know what it is called, but that is where the leak was at. Fixed now.
Still haveing Idleing problem.

[jeffcoslacker]

The ball is the vacuum resevoir. They leak sometimes too.

[starla3366]

I sprayed some soapy water (very unsafe) on all vaccum lines with no sign of any leak or spray back. All vaccum lines look fairly decent, now that I changed the cruise control vaccum line.

Any other ideas?

I don't want to give up.

[kevinb70]

mine was caused by a very low tech issue: the kick panel below the dash was keeping the accelerator from going all the way back. but most of the fast idle problems are usually IAC, IAC pathway, or residue building up on the throttle plate

[starla3366]

Ok, I got some Fuel Injection Cleaner and searched for leaks the right way with no joy what so ever.

Now, since I worked on removing / cleaning / replacing the throttle body / plenum / EGR, I have a paper clip code of "22" (Throttle Body Sensor) along with the same code I had originally "35" (IAC). So, I'm sure most of you are feeling my pain of frustration, knowing I have to R/R a 30$ Part now because I ruined the damn thing when I got it wet probably.

So, Please, if anyone, has any information for me, that would help me through this rough time of mine, please, don't hesitate to reply.

Thanks for your concern,
tony

[Marlamar]

Originally Posted by starla3366

I sprayed some soapy water (very unsafe) on all vaccum lines with no sign of any leak or spray back. All vaccum lines look fairly decent, now that I changed the cruise control vaccum line.

Any other ideas?

I don't want to give up.

What about a low grade electrical short which drains your battery ? and when you start up, your computer compensates for the drain by speeding engine up to recharge low battery. I had a short in my 95-3.1 that did the same thing, really idled fast on startup and stayed fast for a long period until battery charge caught up. I parked it for a couple days and drove my truck and then when I went to start the 3.1, battery was dead . I had never noticed short before then because I had driven it every day, so it always had enough remaining juice to start .. Found the short is somewhere in the chime module circuit, so unplugged fuse and have normal idle and never have dead battery since, just no memory in radio or door open/lights on chime. My be worth investigating to eliminate this possibility...?

[starla3366]

[quote=Marlamar]What about a low grade electrical short which drains your battery ? and when you start up, your computer compensates for the drain by speeding engine up to recharge low battery. I had a short in my 95-3.1 that did the same thing, really idled fast on startup and stayed fast for a long period until battery charge caught up.[quote]

I checked for bad grounds and shorts in electrical wires last weekend with no joy unfortunatley. But, I did check again last night, with no joy. Also read out the battery at 12.08 volts w/out engine on and 14.06 w/engine running. Now as for letting the vehicle sit for long periods of time, I did not start it up last weekened. So I think if it is elecritcical problems causing this, then it would be a strong enough short to drain the battery with in 24 hours. Great idea though.