skipjobe

I have a 383 with a rear mount gt45 about ready to go to the tuner, it has a mail order start up tune. I have been trying to get the car ready for a dyno tune. Here is my problem. The car is running very fat 10to 1 AFR. I have been running the car against the line lock and at about 4000RPM the fuel pressure drops about 20 pounds to about 20 to 25PSI. I am running two Walbro pumps on two different circuits. I checked all the fuel lines and the fuel filter and actually changed the line between the pump and the fuel filter because the line had a couple kinks. Any suggestions would be appreaciated.

98Z28CobraKiller

iTrader: (17)

Not sure if the regulator is in the tank on those but you may have a bad one that is bypassing too much fuel.

skipjobe

I have a fuel pressure regulater and guage at the fuel rail.

98Z28CobraKiller

iTrader: (17)

What's your voltage doing when the pressure drops? You sure both pumps are running?

skipjobe

I don't know the voltage, but one is on the original wiring the other is #12 wire on a relay. there is power to both at the tank but I can't say if both pumps are running i don't have an Amprobe.

skipjobe

I bought an Aeromotive a1000 fuel pump today, I hope that solves my problem.