Went to track tonight, had fuel pressure troubles.

[tangofox]

Took the GN out to the track tonight and I couldn't keep the FP set. I made my first run, and about 1/2 way down the track the car just lost power. When I got back in line, the first thing I checked was my fuel pressure. It was a paltry 36#. Now I had it set at 45#. How could it drop so much? I adjusted it up to 44-45# and made my next run. car ran a little better but sill died. when I checked it again, it was 40#. what the hell could cause my pressure to fluctuate so much? My scan master was showing that it was lean (o2's in the 670's). Finally I cranked the fp up to 52# and got a decent run, not great but decent. It was still lean though. What could cause this suddenly? Also, when I recapped my dump tube on the ride home, my o2's were showing it as rich.

 

[BUICKTR]

Check your hot wire maybe ground is loose. Or it could be possible your pump going bad.

 

[Turbo__Tim]

If you ever ran toulene without lubricant you may have damaged the pump. Put a smaller fuse in the hot wire, and see if it blows. As the pump gets worse, it will 'short' and blow the 20 amp that is in there.

Just guessing, but if you blow a 10 amp fuse the pump is suspect. If you can run a 5 amp fuse at WOT, then maybe the regulator? They do go bad..

Perhaps someone knows the amp pull on the pump. That would be a great place to start.