So I have been running the DIYPNP MS2 on my '00 NB for a while now and things are running well.
I have also got the turbo conversion all finished and a reasonable tune in place (running low boost 9/10 psi).
I thought it was time to finish off all the small stuff and get the car a little more refined but now have run into an issue with the IAC PWM valve. I see a lot of people have trouble tuning closed loop PWM but I am having a problem before even getting this far, its like my valve isn't responding to the ECU.
So I set the ECU to PWM warmup only as some have suggested, but the valve doesn't seem to be doing anything.
I thought the valve might be dead so with the engine running I disconnected the wire to the valve and put 12V across it, you could hear a click as the valve opened and the revs shoot upto 4-5000rpm.
Put a multimeter across one of the pins that usually go into the valve and there is a constant 12V as you would expect.
Put the multimeter across the two pins and get 7.5/8.5V, about what I would expect to see with PWM (unfortunately I don't have a spectrometer to check this 100%).
I found there is a Idle Valve Test so ran this but no changes I make in this do anything at all.
As a test I enabled the FIDLE in the output settings and the ECU throws out 12V to the valve and revs jump up to 4-5000rpm.
So now I am a bit confused.
I know the ECU is actually connected to the valve but I cant control it correctly. Has anyone come across something like this?
I'm pretty sure the valve was working fine on the original ECU about 6 months ago.
Is there anyone out there that might be able to shed some light on this?