Adam Mowafy

Ok I've dealt with all the problems that an isv can have in my time owning this car:

1- ISV needs to be cleaned
2- ISV needs replacement
3-Temp sensor for idle control box needs replacement
4-idle control box needs replacement
5-throttle switch needs replacement


so yes, All these parts have been replaced but after I did the EFI conversion I just left the ISV unplugged because it started acting like it was bad again (wandering idle). but I bought it new last winter.... so I sure as hell hope its not bad already?

well, with winter here and the temp being 15-20 regularly around here these days, it would be nice to have a working ISV. Kinda pointless to have a car with remote start if you have to give it gas upon startup to keep it running

Anyhoo, this is what's going on when the ISV is plugged in:

After letting off the gas (with no load on engine) at like 3k rpm or lower, the idle will either drop extremely slowly or stay exactly where it was.

Kinda wierd when you let off the gas and the rpms dont drop at all......


I tried swapping brain boxes again but that didnt solve the problem. Only thing I can think is maybe the throttle switch is'nt closing all the way? if that were the case would it cause something like this to happen?

Thanks dudes.

CARSNPLANES

I'm not sure what effect the EFI conversion did to the total running effect but standard CIS speaking, with everything working as advertised, known good parts etc, if the idle is high, wandering etc, it usually means that the engine is getting air from someplace else besides the ISV. I'm sure you know there is a "idle" screw near the mouth of the intake manifold that is supposed to be screwed in all the way. Many times this screw has been opened slightly to mask bad idle problems, many from bad ISV's that are clogged and not letting the proper air in at idle. It normally doesn't cause "wandering" idle, just high idle because of the extra air path.
Also. the air line to the ECU has a filter that can either be loose, clogged or cracked. This will cause a faulty signal to the ECU. Use a vac tester to test the integity of the line. I would block off one end and pull vacuum from the other. Naturally, include the plastic filter in the test.

Adam Mowafy

Well when the ISV is plugged in I have to turn the screw back down to get the idle back to where it should be. I had to adjust it due to no isv......


Vacuume is good at ecu.


Any other suggestions? C'mon someone has to have some ideas

Even if the theory of relativity is all you have to offer, I'll take it.

rooster 2

Adam with all the Audi parts that I would guess that you have hanging around, I would think that you have an extra ISV. If you haven't already done so, install that extra ISV, see if that fixes your problem.

shortyq

Test the idle switch. 3ohms resistance is the limit. Also test it with radial play of the tbody while car is hot.

Then, the next step is to go after the pins for the switch in the computer. I've seen those wires sever a couple feet from the switch.

HTH

Scott Justusson
QSHIPQ Performance Tuning