my old car a 78 100 5 cyl 2.0litre has for as long as i can remember require excessive cranking before engine will start either hot or cold engine will turn over between 17 and 25 times before firing, the fuel pressures have been checked all ok leads plugs cap etc all ok been 2 Audi dealers numerous times to try and fix one said in their eyes and Audis "Acceptable" Car runs well when it does start early today had nearly 120mph out of it. I am thinking just thinking maybe not fuel related at all and wondering if the Hydraulic tappets are leaking etc and need time to refill and open valves one other strange thing is if car is parked facing downhill it appears to start alot better although not perfect, fuel been syhponed back to tank??? Now also got a A6 2.6 V6 . Any ideas anyone

 

I am assuming that your car is a European 100? Is it carburated or mechanical injection (CIS, K-Jetronic)? I am tempted to say vapor lock but this would usually mean a hot start problem. Another problem might be your car is not holding the fuel once you shut off the engine and it drains back into the tank.

I doubt that your car has hydraulic tappets, anything before the 80's usually had solid lifters. Too much oil pressure can cause the valves to stay open. Give me some more info maybe I can help you out. I have worked on various versions of K-jet.

 

I believe it is highly likely that you need new fuel injectors. I have an '89 200 Turbo which used to take 5-7 seconds of cranking to start it. This was a problem for a long time even before the car had many miles on it. After replacing the injectors, the crank time is down to 1-1.5 seconds. The car also has better acceleration and fuel economy. I believe that injector problems in the 5 cyl Audis of this vintage are fairly well documented. I hope this solves your dilemma.

Audifan1989