Going through the car trying to get it running.

Looks like the AAV isn't working properly.

First pic is room temperature 75 to 80 deg. F. How far open should it be at this temp?

Second pic is after 45 minutes in the freezer. It is open a bit more but clearly not fully open.

After 20 minutes in the oven, it was completely closed as it is supposed to be.

Thanks.

RT

 

Anyone?

 

Damm brother take it to the dealer. Putting parts in the oven...

 

RT...good way of checking the AAV (also called "secondary air gate" in the manual). I think you're in the minority for taking a wrench to the Turbo around here ;-)

I had mine fail recently after going to solid motor mounts. Another way of checking the AAV is to supply a 12 v power supply to the terminals. This might be a better way of checking since the voltage changes the valve more then the engine temp will (faster that is). In my case the valve was stuck open so I went ahead and took it off. Car still starts OK but the idle needs throttle maintenance for a few seconds at start up.

I'm a minimalist and like to have only the parts I really need. Said another way is I was too lazy to get a new one ;-)

 

Thanks for the input.

Dealer? Most of them probably know nothing about cars this old. That wouldn't be fun anyway. Right now I have the intercooler off, the rear bumper off, and a fuel pressure tester rigged up.

Since I am going to keep it until I die, I want to know everything about it. I have most all the manuals including all the Porsche shop manuals on cd.

Getting her running clean is standing in the way of a K27 HF and headers!!!

RT

 

It looks OK to me. I can't remember exactly, but I know that it didn't move much from room temp to the freezer, but moved a lot in the oven.

What's the car doing to make you suspect the AAV?

This part is also called the AAR by a lot of people. You can probably get more info on the 911 Turbo forum or from Pelican. This forum mostly has the 3.6 guys, and there's more CIS info in the forums for the older turbos.

Here's a good link:
http://members.rennlist.com/jimwms/CIS/CIShome.html

 

Very cool! Sounds like you have a good upgrade in process!!

Just curious...do you have a wide band AFR installed? This was by far the best money spent so far for me. Should have done this a lot sooner. Can't say how key this has been to understanding and tweaking the system. If your car runs like mine...you will be lean at the high end with out some "tweaks".

 

When my failed the idle was stuck between 1500 and 2000 rpm. If it sticks, sometimes tapping with a light hammer will fix it (temporarily).

 

My car will idle low when it is cold, and high (about 1100) once it gets really warm. Could the AAV/R be the culprit?

Bill

 

mine is in the box of surplus bits as i change to efi, if you need one that is, or any of the cis injection system for that matter as the pile is quite impressive ! just to add mine is a 3.3 and getting very very close to completion at long last if the post office would deliver my last few bits !!!!

 

When my AAV broke (high idle) for the second time in two years I just plugged the pipe going from the intercooler to the AAV, it hesitates at bit at cold start but not much.

 

The AAv is supposed to supply more air when cold to stabilize the cold operation since the mixture is rich until warmed up .AAv valve that has failed usually will idle poorly when cold (too rich) because it is not suppling the additional air needed at that time.
It can also go the other way by alowing extra air when it is warmed up (high idle or hunting because it is too lean.)
Sounds like what you describe ? usually one or the other not both.
Elliot

 

Don't have me banned for posting in the superior 964 Turbo Forums, I'll slither back under my 930 rock in just a moment...

FWIW, I pulled my AAV just for ****z and giggles. Car was running fine, no idling problems, cold and/or hot. I just like removing things...it's a sickness, I think, I hate clutter! At any rate, it ain't going back on!!!!! The idle on cold start-up is just a tad low, but soon gets where it needs to be after only a few seconds. Granted I'm in a stable NC climate, but even when the temperatures drop, it's doubtful that I'll need this liitle charm! Yet another fine piece for my collection of spares!

By the way, the thing was full of oil, probably from when my original turbo went bad and sent oil spewing into the intercooler.

Okay, now I'm returnning to my cave in the 930 landscape, "lurking" status, ON...

 

No one has a comparison for how open theirs is/was at room temperature?

 

Wheres that thing sit in the engine????? Also RT whered you get the mauals on CD????

THanks
JERRY