Idle trouble - Time to fess up...

[ZOA NOM]

UPDATE-

Picked up the car today from my mech. CO adjustment AFU. Properly adjusted with gas analyzer. Purring like a kitten right now. I'll be holding my breath when I turn the key tomorrow morning.

[Doug Steinel]

It sounds like you got the problem licked. Congrats!

[ZOA NOM]

I sure hope so. Thanks

[stlrj]

Not clear on what kind of idle hunt you had. Was it a fast hunt or a lazy slow one?

Joe

[ZOA NOM]

It was actually both at times, depending on my idle screw setting at the time. I found myself adjusting the idle screw almost all the way in when it was cold, which would significantly reduce and shorten the duration of the hunting. I'm happy to report the CO adjustment seems to have been the final piece of the puzzle. She was steady as a rock at 4am today.

Edit: the idle would vary from 600 - 1500 in a fairly quick rythym, and settle after approximately 60 seconds if left alone. If I adjusted the idle screw nearly all the way in (CW), it would recover and idle normally with 10-15 seconds.

[stlrj]

I suspect you may have a very common vacuum leak to be found on 3.2's in the form of loose intake manifold nuts that allow that extra air into your engine bypassing the idle air adjustment screw causing the fast idle hunt.

Just a hunch,

Joe

[ZOA NOM]

No leak, Joe.

It turned out to be the CO adjustment. Once my mech put it on a gas analyzer, he found it was severely rich, causing the hunting idle. Once he adjusted it back to normal, it starts and runs steady as a rock, cold or hot.

[stlrj]

Good to hear it was that simple!

Cheers,

Joe

[vash]

hooray!

[cantdrv55]

Let's go for a drive!

[scottb]

Zoanas:

I had the same hunting problem in my 84, and did almost everything you did (new ICV, head temp sensor, O2 sensor, etc.). Like you, my problem turned out to be mixture. Sometimes the easiest solutions are the best.

Now, go drive!!

Scott

[ZOA NOM]

Still purring...

Just a bump for others having similar problems.

[vash]

let's lower that car!

[ZOA NOM]

I'm thinking the same thing, vash. I just don't have a weekend clear for a couple of weeks. I'll keep you posted.

[cantdrv55]

Hey, I want to lower mine as well. Let us know when you're gong to tackle yours.

[ZOA NOM]

cool, here we go again!

[WydRyd]

Hmmm, mine does a similar thing, but it's intermittent. She hunts and then stabilises, but sometimes while she hunts, she'll drop to about 400RPM's nd then stalls. Grrrr! It's annoying! I disconnected the Oxygen sensor though, so the Motronics runs the mixture richer than normal. The GT2-EVO CAMs aren't really helping either as the idle is even lumpier than when it had the stock Carrera CAMs.

[indigowhale]

Hey I am having the same exact problem after installing a new AFM.

Will get the CO% adjusted and report back about the hunting being cured.

I have been thru all the air leaks possible, even a new oil cap seal.

will report back but thought it good to wake up this simple-solution thread--unlike some others, where I learned a lot!

[ZOA NOM]

Still steady after all these months. Good luck, indigo, I hope it solves your problem. Hunting idle is the most frustrating problem I've had so far, but it did force me to dive in and learn some things.

[wanabe911 owner]

Does the Bently manual have this pocedure outlined? My friend has a gas analyzer, and im having a similar problem