Expert: Stephen Sokol Date: 2/11/2007 Subject: Jetronic Aux Air Valve / Idle Performance
Question I'm shining a flashlight into my 1984 Alfa Spider's Auxiliary Air Valve. How wide should the opening be at 30 degrees-F? Mine opens like a peice of pie, and less than a quarter of the area of the circle opens at that freezing temp. When hot, it closes completely. Is this how they're supposed to operate?
Reason I'm looking at is, I've been having idle problems. If my Alfa sits out all day in the sun, it starts up instantly, then dies. Over and over. In that case, once I get it running by applying throttle while turning the key, it's totally fine the whole drive home. Starting in a COLD morning, it starts instantly, then ALMOST stalls, then is fine...
Answer About half the area should be open around 30F. Any Bosch air valve will do so get the best price. You could also try advancing the timing 4 degrees, and make sure the warm idle is 1000rpm. Readjust the idle co screw on the air flow meter to slightly richer (turn in--clockwise).
