Originally Posted by skipjobe
I have a 383 fuel injected 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.
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Fat? You mean lean right?
What size lines do you have going to the pumps and reg?
Do you have a bypass or a vacuum controled regulator?
Sounds like a fuel regulator problem to me.
On a Vacuum controled unit , make sure you have full manifoild vacuum going to it.
Also check for a voltage drop to the pump(s) and also the pump grounds.
Cp