3.2 died constantly when shifting into neutral!
 

The Vehicle- 132K mile '86 3.2 Carrera Coupe- New fuel filter, cap & rotor, plus SW Chip, ECM, plugs, O2 sensor within the last 4 years. Always idled at 880 when sitting (albeit with some tiny +/-25 rpm fluctuations)

The Issue- Now out after Winter storage, she wanted to constantly stall when coming to a stop or slowing. Push the clutch in & take it out of second while on the brakes and the engine would fall to under 300 rpm and then die. She would always start immediately again (even while coasting).

All possible vac leak problem areas either new or in good shape- including the oil breather tube adapter and that wacky brass/breather thingy (#93011032803). Checked the actual vacuum using the Heidi & Franny's Garage recommended left side fuel pressure regulator splice with a vac gauge. Result- More suction than a Dyson on crack.

Through questionable process of elimination, I then cleaned the ICV. While that seemed to help, it really didn't change the overall issue. ICV did appear to be working (it did hum with the ignition on and obviously held an idle while sitting).

Checking the records, the ICV was last changed in 1996, so it was now 22 years old. Based on other posts, I went ahead and bought a brand new Porsche ICV #930-606-161-00 from our host.

The swap took 10 minutes. I now have a new car. Seriously- the change in drivability is dramatic. Smooth, even and wonderful. Rock solid hold at 880 when slowing down and shifting into neutral. She even sounds better. Hell, I'm convinced the ICV swap also took 10 lbs. off my weight and I have more hair. I couldn't be happier.



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Congrats on solving the problem.

pelicans price is very good. My wholesale price is $305

Thumbs up for posting a problem and your solution! Thanks.

Congrats !

The electronically controlled idle device such as the ICV in the Motronic is a great improvement over the previous designs.

how is icv unit holding up? any stalling issues appearing? if not, great!

That is ~ .01 second on the ¼ mile...

Hi @lonekiawe- Still running great- no stalling issues- very happy. I also did purchase new (correct) Porsche hose clamps from our host (trying to keep everything period correct)

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most people change the ICV when it is DOING its job. that is the idle is surging, not that that's correct, but something is usually telling the icv to vary the idle. this is probably one of the most miss diagnosed parts. I might second a voltage reg.

your case it WONT idle. usually a stuck ICV or just bad. good job

Hi All- Just a quick follow up- now at 164K miles. It's been 6 years and 32K since the ICV swap, and I noticed in the last two days (and only when the A/C is on) that she would stall about 30% of the time when shifting into neutral. RPMs would drop below 300 (again, only with A/C on) and flatline. Pretty maddening, but she would then fire up immediately. The last ICV clean was at 154K miles (2 years ago). Hosed down the ICV internals and did the shake-shake. An absolute Night and Day difference. The most surprising characteristic (post-clean) was the lack any of rpm drop. Once again, rock solid. A clean ICV is a happy ICV.

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http://forums.pelicanparts.com/uploa...1721259253.jpg

Cooking on a Porsche 911- The herbal butter made the difference.
https://www.youtube.com/watch?v=FvXBR50rH9E
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How badly gummed up is the ICV to cause this problem ?

Post a pic of the internals if you have them.

Hi Pmax- It didn't look too bad on the inside, but it took some degree of shaking before I started to hear the distinctive clack of free movement.

Thanks, one of these days, I need to take a look at the ICV in my 87 but then it has been running flawlessly ... though it is right there and easily accessible thanks to the thoughtful design of the Motronic system. Berryman makes some good stuff. I use the B12 on my DDs regularly.