Fuel pressure running off at the worst time

bert powell · 02-24-2012, 10:05 AM

Guys, been aggravated with this problem on and off for a while. I have a GT/CA Camaro with a Qjet, Magnafuel 500 pump and the large 2 port reg. I added a fuel guage at the pump and was getting 26 psi at 12v. When I switch to 16v it would peg the guage over 30psi. So I tried to reduce the pressure and when it did come down the pump bypass would leak because it was screwed out too much. I cut two coils off the bypass spring and got the pressure at 26 psi at 16v. Reset the front regulator at 6 psi and went to test. First run fine. Second run, after the burnout the front pressure went to 12+psi. Got back to pit and cycled the pump, sat there at 6psi and would not move. Going to check the regulator for trash again but did not find any before.

Anyone used the Magnafuel large 2 port regulator before without issues? Thinking about changing it.

How much can I lower the pump pressure and still be safe, thinking about dropping it to 18psi.

I had a carb fire trying to get the thing down the track before and would like to fix this permanently. Any ideas?

02-24-2012, 10:05 AM	#1
bert powell Member Join Date: Jul 2002 Posts: 243 Likes: 36 Liked 34 Times in 12 Posts	Fuel pressure running off at the worst time Guys, been aggravated with this problem on and off for a while. I have a GT/CA Camaro with a Qjet, Magnafuel 500 pump and the large 2 port reg. I added a fuel guage at the pump and was getting 26 psi at 12v. When I switch to 16v it would peg the guage over 30psi. So I tried to reduce the pressure and when it did come down the pump bypass would leak because it was screwed out too much. I cut two coils off the bypass spring and got the pressure at 26 psi at 16v. Reset the front regulator at 6 psi and went to test. First run fine. Second run, after the burnout the front pressure went to 12+psi. Got back to pit and cycled the pump, sat there at 6psi and would not move. Going to check the regulator for trash again but did not find any before. Anyone used the Magnafuel large 2 port regulator before without issues? Thinking about changing it. How much can I lower the pump pressure and still be safe, thinking about dropping it to 18psi. I had a carb fire trying to get the thing down the track before and would like to fix this permanently. Any ideas? Last edited by bert powell; 02-24-2012 at 10:07 AM. Reason: additional info