I recently bought a 1993 90cs quattro 2.8L V6 5speed 115,000miles. I have never owned a german car before so this is all new to me. I have come close to running it out of gas a few times in the past month(I have become accustumed to having an idiot light to tell me it's low on fuel). Anyway starting has become erratic. The check engine light has been coming on and off since I've owned it but I don't know if it has anything to do with my problem. If it is going to start it will do so the first time you crank the motor and once started it runs fine until you shut it off. Then when you try to restart it will try to fire on the first revolution but then it's a lost cause if it does'nt fire right away it's not going to fire again until you walk away and try the next day. Get back in it the next day and it will always fire on the first crank but it will only start about 50% of the time. I thought maybe I have a fuel problem filter or pump due to running it low on gas. I just got it started for the first time in a week let it run for about an hour while I cleared the 2ft of snow out then I took it out for a little rally in the snow brought it back turned it off and restarted it twice and it started fine the third time it would'nt start. It's been 15 degrees out so I have'nt tried to diagnose it yet. Not sure where the fuel filter is? Does it have a fuel pump relay that could be erratic? Whats an easy way to see if it's getting any fuel? Is there a way to test the fuel pump? Maybe it's not a fuel issue maybe it's not getting spark. Anyway sorry for the long winded explination just woundering if this is something common and if anyone could lead me in the right direction.
thanks for your help
tmarch

 

check for pin holes in the fuel lines this will cause the fuel pressure to drop hence the none starting, the pump will cycle for a couple of seconds then when its up to pressure it will stop should you hear it running longer then suspect a fuel leak, this is a first part of the check list because many things without fault codes is just a guess

 

When I turn the key to on I can't hear the fuel pump in the rear. I do hear a click in the front 2-3 seconds after I turn it on. Could this be the relay or is the fuel pump in the front. it's hard to tell because of the chimes from the insterment panal. Also where can I find a good cheap service manual. I see cheap cd's on ebay for $10 are they worth it?
thanks
tmarch