My 760 Turbo has developed an intresting problem - something is overheating, and causing the car to die.

What's happening is that after driving the car for about 20-30 minutes, it starts to hiccup under load, as if it's not getting enough fuel (tach drops abt. 500 rpms). As I keep driving, the condition gets worse until it will just die even at idle - stepping on the gas only buys a few extra seconds and then it will just sputter and die, and the whole dashboard lights up. If I then just wait for 10 - 15 minutes I can drive it again for another 10 - 15 minutes before it dies. During the wait, the car will restart for a second but dies immediately, and the more time passes, the longer it stays running it seems. Cracking the hood open seems to speed up the recovery time.

Ambient temperature seems to play a major role in this - the colder it is, the longer the car will run. I spent 45 minutes flogging the car in +35F weather before I got it to sputter even slightly. Crawling in traffic at +80F speeds up the onset and severity of the problems.

When the vehicle died a while back I tried swapping the FI & AC fan relays, no effect. I pulled the AMM plug and it did not restart. I listened for the main fuel pump when I tried restarting, and it was making noise. I believe the fuel pre-pump may have failed, as there are no changes in sounds coming from the tank when I pull the fuse. Last weekend I swapped the power stage & ignition coil, and cleaned the throttle body.


Would anyone care to take a stab at this? Right now I'm thinking the next thing to get swapped is going to be the fuel pump relay...