I know this has been covered before. I have read the threads and still am confused. I own an '81 GTSi. It seems to start fine in all weather, but it does not go through the fast idle during warm up. It idles around 800 rpm until warm, then it settles around 1200 rpm, but is a little rough. With the throttle open it runs perfectly. I thought this might have to do with the fact that the pyrometer sensors are not being used due to the cats being removed. They are just hanging below the mufflers. But then I found out the car was running rich at idle and I read the threads about the AAV/WUR problems. From what I can gather, the AAV controls the fast idle, and the WUR controls fuel pressure. Since the fast idle is not engaging, I am guessing that I should check the AAV first. Is this correct? And is there a procedure to check it other than just taking it off and seeing if it is stuck? And would reinstalling the pyro sensors make any difference to anything? Thanks for any help.
The AAV is dead simple. When it is cold it should be open. When it is hot it should be shut. When it gets 12V the heater should warm it and cause an open cold AAV to get wam and close over the course of a few minutes. That's all there is there.
If you want it to go to fast idle yes check the AAV. I personally don't like my car to idle at 1600-1800 when dead cold so I bypassed mine. My car starts up and idles around 950 rpm. The car runs great even right away. The Warm up regulator is what handles your cold enrichment.
You are where I was in Apr. of this year! I purchased a neglected 82 GTSi and have been learning about the FI system ever since. This is the right place to get the info you need. First to answer your question and I quote from this forum "there is NO intelligent connection between the thermocouples and the FI" they only operate the slow down lights. I also removed the cats and all the smog crap. May I suggest the Bosch FI manual and also look for threads by Dave Helms, Magnusson,Fastradio and a few others that have answers and not opinions. There is a wealth of info here but also an equal amount of mis-info. It took a few months and the purchase of a gas analyzer, CIS pressure gauge, injector testing gauge and this forum but she is running sweet and I can drive with confidence----------------- go for it , it's not that complicated! Notsolostanymore
