Carrera 3.2 idle fluctuation

[Zef]

OK guys...There are the results...I removed the ICV...cleaned it in a ultrasonic bath...put some light lub inside. I mesured the resistance IAW Bentley manual...All was fine at 40.7 ohms for the outside to outside pins...21.3 and 19.8 ohms for the center to respectively outside pins. I mesured the voltage from the DME at 12.7 V. I reinstalled it and started the engine with my can of ether on hand. Right at the start, the engine idled smoothly...I sprayed some ether at the strategic points with no raise of the engine RPM. So...the culprit was finally the idle control valve. After 25 years of modulation...it was ready for a good clean up...Thanks to all that help me on this one...Syl.

[Booney1golf]

When the culprit is fixed and traced, the idle mixture needs to be adjusted to the correct ratio, so at start up, it will naturally idle nicely at it's expected speed, and need little to no correction assistance from the idle control valve and O2 sensor. Mixture adjustment is performed with an air bypass screw under the air flow meter with a 3 mm allen wrench. After setting the correct mixture, the base idle speed needs to be adjusted to the correct operating window of about 880 rpm. This is done at normal operating temperature on the throttle body. Jumper the b-c terminals on the test socket on the left side of the engine compartment to lock the idle stabilization valve at 50% duty cycle so you can adjust the base idle speed to the middle of the ISV's operating window.

My 3.2 has always idled very irratic. Every other time I adjusted the air flow meter / air bypass screw I did not use the above mentioned jumper and it did not work.

Last night I adjusted my idle using the above mentioned procedure and for the first time in 3.5 years my car purrs like a kitten.

This forum is great thanks to you all and I hope you take a few minutes to follow the above procedure then you will realize how smooth your engine will run!!!

Best regards,
Daniel Womack - Booney1golf
1985 Porsche 911 Carrera Targa - If you think golf is addicting try a Porsche

[mmn710]

I'm actually having this same problem as we speak but my sometimes likes to stall on me when idling. I have a whole write up on my car on another post if anyone would mind looking at it and giving me some advice there if i need something done diffrent. Thank you.

Finally got the 88 3.2 out of the garage after 5 years!!

[pete-stevers]

funny thing is i have been watching this thread cause my 87 stopped idling the other day after a back fire....i am going to take close look at it tonight....
thanks for all the info guys

[DRACO A5OG]

Just replaced my ICV for $125 ten minute job.

I metered mine it definitely failed. Now it actually idles 1200RPMs at cold start then 30-45 seconds later drops to 770=800 RPMs. The way it was supposed to. Very happy never had it warm idle before.

Thanks Loren for the ICV test!!!

[brownfox]

Seven years later, this thread still works! Had similar problem with my 60,000 mile '88 Targa. Took off the ICV; it rattled a bit, but sounded muffled. So I sprayed it with contact cleaner (closest thing to injector cleaner on the shelf). Extra fluid spilled out black and the rattle sounded sharper. Put it back together. Started up; idle loped steady between 800 - 1200. Better than before, but. Now what?

Got ready to take ICV off for more cleaning…Hey dummy! The electric plug's not fully seated. Fingers crossed, fixed it. Hope that'll make a difference.

Restarted. Idle now steady about 800. No miss on acceleration.

Thanks to all for an easy, simple fix.

[DRACO A5OG]

In addition to cleaning, you need to check the Ohms for proper resistance.

LOL, I wrote "metered" what a noob :-P