Idling Problems
10-11-2007, 11:22 AM
#1
Instructor
Thread Starter
Join Date: Feb 2004
Location: Australia
Posts: 196
Likes: 0
Received 0 Likes
on
0 Posts
Idling Problems
My '86 951 seems to be experiencing intermittent idling problems. This problem seems to come and go - some days the car idles perfectly, others its every time I start it (the car is not used everyday). The problem occurs only after the car is started, never when idling in traffic. It does not seem to matter whether I was just driving a few minutes before or on start up in the morning - sometimes the car just refuses to idle steadily. Air temperature / weather seems to make no difference. The car usually idles around 950 rpm, but when the problem occurs rpm will be around 500 or so, and the car is on the verge of stalling. When this happens I give it some gas and it corrects itself after 10 or 20 seconds.
My question is, what could be causing this? Maybe a dirty idel stabiliser valve? (The car runs Guru chips and the DME relay is fairly new).
All thoughts greatly appreciated.
My question is, what could be causing this? Maybe a dirty idel stabiliser valve? (The car runs Guru chips and the DME relay is fairly new).
All thoughts greatly appreciated.
10-11-2007, 01:47 PM
#3
Sounds like the ISV, get rid of it, I did, just give it a little gas on cold start and adjust the idle when warm, mine is perfect at 1,000 rpm in the middle on idle, feels better and less space taken up under the intake manifold with that heavy metal ISV out of the way and two less hoses that go with it, plug the port on the intake and the IC pipe to throttle body with a blocker and you'll be fine...less components, less complications...
10-11-2007, 03:48 PM
#4
Nordschleife Master
Take out the ISV. Cover one side and blow through it. If it leaks replace it or put epoxy around the seems so it no longer leaks. Thats what I and a few other have done. I think the cheapest place to get one is paragon for about $150
10-12-2007, 04:40 AM
#5
Rennlist Member
Sounds like the ISV, get rid of it, I did, just give it a little gas on cold start and adjust the idle when warm, mine is perfect at 1,000 rpm in the middle on idle, feels better and less space taken up under the intake manifold with that heavy metal ISV out of the way and two less hoses that go with it, plug the port on the intake and the IC pipe to throttle body with a blocker and you'll be fine...less components, less complications...
I say take out the ISV and try giving it a good cleaning with some WD-40 that will loosen up the gunk in it. Be sure to drain it out well and see if that helps any. Otherwise, I'd consider checking the throttle position sensor.
10-13-2007, 12:41 AM
#7
Perhaps, but you live in Florida. Running these cars sans ISV in colder climates is no fun.
I say take out the ISV and try giving it a good cleaning with some WD-40 that will loosen up the gunk in it. Be sure to drain it out well and see if that helps any. Otherwise, I'd consider checking the throttle position sensor.
I say take out the ISV and try giving it a good cleaning with some WD-40 that will loosen up the gunk in it. Be sure to drain it out well and see if that helps any. Otherwise, I'd consider checking the throttle position sensor.