ICV delete??

**Texaslonghorn1** · 08-31-2018, 11:34 PM

I've searched here, r3vlimited and Google in general and haven't found an answer to my ICV question. I have a 91 M42 1.8L that idles like crap with the ICV in and when I delete it then connect the vacuum hoses together. When I pinch the hose, idle stops revving and goes down to an acceptable level. The car isn't a show car or even dead stock - my son wants to make it a toy to race or drift. What would happen if I just capped off both the vacuum hoses? Will that vacuum loss in the overall system create other problems? I live in teh south and the car won't be driven in cold weather anyway, so the cold idle issue doesn't really apply.

**richardodn** · 09-01-2018, 10:30 AM

If you have a revving idle, the usual cause is a sticky valve. You can clean it internally with carb or brake cleaner and then reinstall. It does sound like you may have additional vacuum leaks too. You might also check the e36 forum for more discussion about the M42.

**Texaslonghorn1** · 09-02-2018, 12:07 PM

I cleaned the icv earlier and the revving happens even when it is not installed. All hoses and gaskets are brand new (about a month old) and I've checked and rechecked although I haven't smoked it. Thanks.

**BEANCENT** · 09-04-2018, 05:08 PM

When I had the 2.7 eta motor in my e30, I had bad idle issues like yours and saw where a guy took a copper penny and drilled a 3/16 hole in the center and stuck it in the hose that feeds the ICV ,this had the affect of limiting the amount of air through the ICV and caused the uneven idle to become normal. This may not tell you what your actual problem is but it may mean that your ICV needs replaced.