DME Relay and Frustrating ISV

IanHighfield · Oct 23, 2005

I have read that it is well worth carrying a spare DME Relay, so after thinking about it and not getting one, I finally ordered one from Porsche-Apart. Duly arrived the next day and in a few minutes was in the car. The car started straight away and had a crisper more even tickover - can a DME really do this ?

As for the ISV, I had decided to remove and WD40 it as I had read this can lead to the stalling problem I had, along with erratic tickover upon cold start (now almost cured by raising the idle to 880rpm as per advise from Steve Wong and the fitting of the DME).

I removed the airbox and Mass Flow Sensor enough to be able to get a screwdriver at the screws that hold the ISV to the throttle body. Could I get them to loosen - not on your life !!!

So frustratingly re-assembled and will assume the ISV is OK for now.

Is there an easier way to ensure the ISV is functioning correctly ?

audicdl · Oct 23, 2005

Ian, if you're referring to the Idle stabilisation valve I think you may have been trying to take the wrong thing off, as it's quite easy to get to without taking the other items off that you mention. I posted a thread about 5 weeks ago as my engine sometimes cuts out when you press the clutch,when cold. On that thread someone kindly posted a photo showing the location of the valve if that helps. I cleaned my valve and alas it made no difference. Are your symptoms similar?
Chris

IanHighfield · Oct 23, 2005

Good call Chris - very similar symptoms - I was trying to remove the wrong thing. Teach me to follow poor diagrams as I thought I was removing the correct thing.

Took two minutes to remove the real ISV and gave it a good spray of WD40.

In reply to your previous thread, I am not sure how to test it. I connected mine whilst off the car and it 'vibrated' (not exactly sure about the plopping noise, but it does sort of open and close)

Have now replaced and car starts and runs fine - will try it out from cold tomorrow.

Did you ever get the electrical test info from Nessie ?

audicdl · Oct 23, 2005

No, not as yet although I must admit I'm beginning to wonder whether it is a characteristic as opposed to a fault as some road tests that were written in the eighties seemed to pick up on the stalling when cold. We'll see.
Chris