fuel pressure regulator question

[tmracing62]

Sometimes even the best fuel pressure regulator gets hinkey for a minute, but sometimes mine will jump to 10 pounds (set at 6 1/2) when the pump comes on. It forces the needles off the seats and if it doesn't start right away, it can take a bit to get it started.

I have two Barry Grant 4-ports. One is brand new, the other rebuilt. It happens no matter which one is installed. Magnaflow fuel pump constant 24 psi on the inlet side, reading it right off the gauge. It can happen when the engine is shut down and immediately restarted or after sitting all night.

Any reason or cure you know of?

[walkerheaders]

the magnaflow pump should have a -8 bypass and hose back to the tank. mine does. the bypass is adjustable. send way less presure to the regulator like 10-12 psi. you'll still have the volume you need but not that extreme pressure.

[jester]

I installed a manual switch to shut off the fuel as well as the oil pressure cut off switch. When I start the car, I shut the pump off to avoid that problem. Than after it starts, I burp it once or twice . That's what I use as a fix.

[tmracing62]

Totally sensible answers.

Bob - I turned it down to 20 psi on the inlet side. Past experience has taught me that lower than that and there may be a nose over or lag under instant acceleration - like coming off the trans brake.

Jester - Since the pump is wired into the ignition, I cycle the pump on-off-on-off until it settles down. Having a cutoff as you suggested makes more sense, but I have gotten lazy and tried to avoid the work. Have considered putting in a switch box on the windshield cage bar so the pump and the ignition/starter are separate. Again, just lazy and avoiding a rewire.

But thanks to these ideas, I'll get it.