ok, took my LB9 engine on a little trip today. On the way back, I kept losing fuel pressure such that the car first would not accelerate, then would try to (and sometimes) die. Since I was 100 miles from home, it was a long drive.

If i was crusing down the NYS thruway at 65 mph, every 5-9 miles, it would try to die, as soon i felt the power fall off, I would hit the clutch, shut the engine off, wait a second, turn the ignition back on for 2 seconds, then re-fire the engine, all at 65 mph..... I could do this every 5-9 miles and got back.

I put a fuel pressure gauge on when i got home and went for a drive, after driving a couple miles, my fuel pressure would go from fine (38psi) to 0 in a couple of seconds. Again, I could re-fire the car on the roll.

Worked on it in the garage, after 5 minutes of running, you would all of a sudden hear the pitch of the fuel pump get higher and quieter while the fuel pressure dropped off to zero. Fuel pump would continue high and quiet while making no pressure. My only guess is the motor is turning but not the rotors...... shut it off and wait, then re-try and the fuel pump would get louder, lower and build fuel pressure...... Time for a fuel pump change?

Also, when i shut the fuel pump off, I get a gurgling in the tank for about 3 seconds.... not sure why.... the fuel pump usually, but not always, holds the fuel pressure.

Who agrees that I get the wonderful chore of dropping the fuel tank?

thanks

 

Fuel pump is sucking something up, so that it can't draw fuel.

 

There is a dampener between the pump and the rigid pipe in the tank. This piece looks like a bloated rubber hose that quiets the pump somewhat. They can rupture and then won't build much pressure if any. Most people toss that piece and replace with fuel injection grade hose and clamps. If that dampener or the pump is the problem it will of coarse mean either removing tank or cutting hole in bottom of trunk compartment.