I have an '93 Audi 100cs and it's worked great until today. It left my stranded on the freeway. I'm just trying to diagnose the problem. My first thought is it's the gas pump, or maybe the relay to it. The car was working fine, then just died completely. It didn't really choke, it just died and slowly rolled to a stop. I can't get it to turn over. All the electrical seems to be okay, except I can't hear the gas pump 'prep'. The car tries to start, and I now know I have a great battery and perfect starter. I just don't think I'm getting fuel to the engine. If you have any suggestions, I'd be extremely grateful. The cars kind of my baby, and I'd hate to have to rip apart the gas tank if it's something else. I'd be ecstatic if it was just a sensor, or relay.

Thanks for all your help in advance.

 

it tries to start?? put some gas in the throttle body direct and if it starts then its down to fuel pump or relay,

check the timing belt as this dead engine syndrome is prominent in these cases

 

The starter turns, but there's absolutely no response from the engine. I'm hoping it's just the relay... that'd be nice. I will shove some fuel into the throttle body, and check the timing too. It's just strange how it happened. I haven't noticed anything wrong, no loss of power, no pinging, nothing. Even as it died it was quiet, it's almost as if it was placed in neutral and rolled to a stop. I didn't really notice I lost power since the engine is normally so quiet anyway. I'm going try and get to an Audi dealership today and see if I can pick up a relay.

 

remove the timing belt cover and rotate the crank then see if the cam turns with the bottom if it doesn't the the belt might be stripped of course I hope not but the way you describe the problem points to this, do that first before spending unnecessary cash

 

I shoved fuel into the throttle body, and it fired instantly. It funny how an engine starts when it gets fuel right? I was wondering if there was a way for me to know if it's the relay or the pump... without just buying a new relay and trying that. Thanks to all that give suggestions. And Avant, you've been a great help man, thanks.

 

you have to have a test light or best a multimiter.
got any of them?

 

Bosch fuel pumps are well known for failing on the early cars around 100k, the same pump is used on the Mercedes/BMW and many other cars