Brain Trust Needed: Fuel System Test Pressure Leaks Down

[Ivoidwarranties 8]

I’m at the ending stages of my build and getting ready to fire up my new engine for the first time. I am using the exact same fuel system including the injectors as I was running before (details below). I was at the point where I would turn the key to ON and let the pump run for three seconds before it turned itself off so I could check for any leaks on the fittings. When I did this in the past (and this morning), the fuel pressure gauge on the regulator would shoot to 63 pounds while the pump was running and then as soon as the pump turned off it would drop to 40 psi and hover there for a while before bleeding off. It would stay at 40 psi for at least a minute or longer.

This afternoon I went to test for any leaks again and the pressure steadily drops to 0 psi after the pump turns off. When the pump is on, it goes straight to 63 psi. As soon as the pump turns off, it drops to 0 psi.

There are a couple reasons why this concerns me. One, it’s acting differently than it ever has before. Two, I heard of someone recently destroying their engine because they “had a leaking injector that filled the cylinder and hydrolocked it when starting.” Their story, not mine.

Anybody have any thoughts on this? I called Fore Innovations and talked to Don. He has no concerns and says fire it up. He says the check valve is not made to hold pressure anyway and it’s just there to keep the lines full for the next startup. I called Dave Weber and he has the same concerns I have.

My plan now is to pull the coils, pull a sparkplug out of each cylinder, and try to determine if there is fuel in any of the cylinders, all in an effort to see if any injector is leaking by.

I’m open to any input or suggestions.

Here’s the fuel system I am currently running. It worked like a champ before the engine swap and I’m happy with the way it was performing.

[Hemi31 194]

As soon as power is cut on the return system pressure will drop like a rock.

[Ivoidwarranties 8]

As soon as power is cut on the return system pressure will drop like a rock.

Thanks for the response Mr. Storms.

I kind of understand that. But every time in the past, it would drop to 40 psi and stay there for several minutes. Why the change?

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And is there anything you do to check for a leaking injector?

[LUV MY RT 2]

My pressure gauge got to where it would drop a little after I cut the power then it would fall but not go all the way to zero. Would stay around 5-7 lbs. I replaced gauge now it falls steady to zero when I cut the power. I have the Fore regulator with the liquid filled gauge. I guess the gauge does go bad even though it is liquid filled.