Hi, Have on-going problem with adjusting tick-over Presently around 2,500 rpm 1.6 Gti - EG Engine. Amongst the boxes of assorted shares that came with the car was a spare inlet manifold. Not the correct one for my engine but there was an auxiliary air valve on it which I have removed. Is there any way of bench testing it? Would like to be sure that to is in working order before replacing the one currently fitted which I believe may be faulty. The rpm drops when the air from the one fitted is restricted with the engine either cold or warmed up. Many thanks
if you look inside the AAV it should be mostly if not fully open, then if you apply voltage to it the valve should slowly close off
Hi, Have checked the AAV, Removed it from the engine Looking through it appears to be partly open Applied 12v to the terminals No movement at all. The engine had not been started for at least 2 years when I first fired it up. AAV possibly seized. Will replace Thanks to all who advised. Very much appreciated.
Hi, Further to my earlier post I tried the AAV again. Put 12v across the two terminals and left it for a few minutes. The body got warm and the AAV closed. This took a few minutes. After I disconnected it the AAV opened as it cooled down. Does this suggest that it is working OK? Cheers
its workign by sounds of it, but it might not be closing enough. i beleive there is some adjustment, but leave that till you're 100% sure there is no air leakign in from somewhere else. if its got a later kjet head with air shroudign system there is a vacuum nipple between cylinders 3&4 on the back of the head, if the wrong injectors/inserts are fitted or if theres missing seals/broken inserts this will elak to much air past the injectors. to test if this is the case clamp/block the pipe to the head and see if the idle drops down noticably. On my 16v I was only able to get the idle to 900 with screw wound all the way in to the stop when I had merc injectors fitted (no top hats as required for air shroudign system)
Thank you again. Did all 1.6 GTi engines have a vacuum booster? My engine was manufactured in or about July 1979. The inlet manifold on mine only has a single pipe to connect from the AAV. There is a vacuum booster fitted which is connected to the pipe from the AAV by way off a home made 'T' piece. The one way valve from the front of the manifold has two small vacuum outlets which seem to be for a fuel consumption indicator and ignition retard neither of which are fitted to my car. Both are taped up. Just doesn't look right. When I got the car there were boxes of bits some of which appear to be from a 1.8 engine. The car was only partly put together the previous owner having lost interest In one of the boxes I found a one way valve which clearly attaches to the brake servo pipe. It has no outlet for the vacuum booster and no small outlets. I was just wondering if this could be the correct one for my car and the other one incorrectly fitted and adapted? If it were then it would solve the issue of the vacuum pipe connections from the AAV to the manifold and the two blanked off outlets. Any help would, as ever, be very much appreciated. Thank you
sounds like its been messed about with yeah, some later bits put on there. Do you have the suction jet installed 067133753A, I have a vague memory that this can cause high revs if missing/broken. heres the best pic I have to hand of it in the GTI vac system: and heres another showing the AAV, it seems to have every possible variation of vaccum setup shown so its a bit complicated, just concentrate on the valve and the 2 pipes which connect to it, and where it joins into the brake booster hose: if you can get yourself a copy of the brown cover mk1 haynes manual you wont regret it, they're very good and it will have much more detail in there
