ISV Revisited

It turns out my idle stabilizer valve (ISV) is shot.

Since I was having such wonderful idling issues I posted to the audiworld.com forums hoping someone would have some ideas. I had some ideas of my own, but it is always best to have a full hat of tricks when entering the garage.

Some kind soul suggested I remove my ISV and blow in one end to see if the gasket was good (no leakage) or bad (some to much leakage). Mine came in on the bad side. The very bad side.

I ordered a new ISV on Thursday, received it on Friday, and was able to install it today (Sunday). Oh. My. Goodness. What a difference! The idle is stable, but the car still idled quite high. So, back to the bag of tricks.

In my perusal of the repair manual I found information regarding a special procedure for changing the CO (carbon monoxide) mixture. It appears some of the CO running through the turbo ends up back in air headed for combustion-land. The procedure calls for removal of a semi-permanent aluminum plug near the fuel distributor, and mine had most obviously been removed. That's right: somebody messed up my CO mixture.

It took some trial and error, as well as proper adjustment to the idle via the throttle body, but I presently have the car starting decent and idling smoothly at ~1100RPM. This is still not where I would like things to be, but it is much better.

The car should be able to start without pumping the accelerator, and should idle at ~750RPM. I'm almost there!