2002 A4 Quattro with automatic.

It won't start. The starter is turning the engine. Fuel pressure seems fine; I think it was about 55 psi with the key on and while cranking. If I crank it long enough, it sounds like it's trying to fire, but I just don't think it's turning fast enough to actually start. The tach is showing about 250 rpm when I cranking. Anyone know what it should be? Anyone want to disconnect their fuel and spin the engine to see what speed they get? I'm hoping it's just a weak starter (or, better yet, a bad wiring connection) and not something more serious with the engine. As far as I know, this is the original starter from 2002. The car has 165,000 kms (102,500 miles) on it. I definitely know the starter is at least 10 years old, because it hasn't been replaced since 2005 when I bought it.

At first I thought the starter was spinning and not turning the engine at all because it was making so little noise due to the slow turning speed. There were no MIL codes when I checked.

 

Wow, I was kind of hoping this was an easy question. No one has anything to offer? I'll give an update.

After messing around with it for a week, I finally decided to crank it for a long time. I was still helping the engine with the starter past 1000 rpm, but, eventually it ran. It ran rough, but it ran. I had already scheduled the tow truck for the next morning, so I decided I would let him take it to the shop. But when he arrived it started no problem. We finished filling the cooling system (which is what I was doing when it died the first time) and everything seemed fine. I decided not to have it towed. I was buttoning everything down and getting the air out of the heater core and everything was fine. At the end of the day, it wouldn't start again. Back to square one. I don't think it is sparking, but will it even spark while spinning at 200 rpm on the starter???

 

I think that the speed of cranking has little to do with your hard starts. The plug will fire at near zero RPM IMHO. If you can scan with VAG-COM, that might be a big help. Also, a slow-starter usually is the result of low voltage, not the starter itself. Look for corroded cable crimps, battery clamps, and the battery's cranking voltage measured at the posts.