axl911

What happens when you turn the ISV a bit too far? What are the affect(s)?

In addition, after adjusting your ISV and driving for a while (so the car adapt itself), do you get a higher idle?

In theory, the car does everything it can to maintain the 800 +/- 40 rpm idle, including closing the ISV more if it has been adjusted to open more. So I am just wondering the effectiveness of the ISV adjustment.

And yes, my car has a lightweight flywheel and RPM does drop a bit too much once in a while.

matt777

I adjusted my ISV last fall after installing a LWF. It did stop much of the stalling but not all of it. My understanding is that the ECU does try to bring the idle rpm down to the original set point, perhaps too quickly, which is the cause of the problem. Steve Wong (911 Chips) also led me to believe that his LWF chip changes these parameters (if I understood him correctly that is). I now have his chip with this LWF software upgrade but haven't been able to try it yet because winter is still here.

Van Larson

Had ISV cleaned when FD installed LWF/clutch and Wong 91 Oct matching chip. Car delivered back to Illinois in winter so just have started driving it. Disconnected battery on several occasions and Wong has an "adapting" protocol when re-connected. First couple of outings got an occasional "stall" when in 4th or 5th, clutch in for a turn--disconcerting when you lose power steering. Having now driven the early 95 4 or 5 occasions, no stall--but the revs do drop low, bounce back up and then settles at about 850 to 900. Might play with the ISV a little to see if I can minimize the fluctuation but as long as no stall, the minor rpm hunt is not real objectionable.

JPS

I had done all that too. Mechanic noticed it not quite right when in for something else, and tracked down a vacuum leak that was causing part of the stalling as well.

TMc993

Frustration, moodiness, dissatisfaction...

Crimson Nape Racing

I have the lwf and steve w chip and adjusted the idle. It still stalls occasionally. Steve wideaid the only real to solve the problem on 95's is to change your driving habits - let the rpm's go down to 1200 or so before pushing inthe clutch. I do not think the OBD1 cars "learn" lime the OBD2's do.