Fprv....

Hey guys,
Just curious if any of you have had trouble with the fuel pressure relief valve on the LLY engines... I have one that I believe is a suspect based on the symptoms encountered.

I have one truck that runs this same tune great, the other periodically bogs down off the line or loses pressure at around 70 mph @wot.... it sometimes does it on less powerful tunes as well.

The truck that's having issues is 360-400rwhp.

Let me know some symptoms that you've encountered if any... thanks! :cheers:

why don't you use the DVT controls while logging to see your pressure, or do the bottle test to verify your suspicions. All can be done in the driveway with no driving needed.

I haven't tried any of the DVT controls, unfortunately this was for a buddy of mine and he doesn't actually have EFI live... and he lives 12 hours away, I just mailed him my stuff for a while.

How would I be able to test the FPRV specifically with the DVT controls unless I was running down the road and creating the same conditions at which the problem is occurring, which are erratic at best.

Also, forgive my ignorance on the topic here, what exactly is a bottle test?

Well the bottle test utilizes the DVT controls.

Basically disconnect the "pop off line" (the pressure relief) hose the dumps the relieved pressure into the fuel return line from the CP3, and put the line into and empty 20oz bottle and ramp the pressure up with the DVT control while at idle in the driveway. if the FPRV is bad it will pop and dump fuel in the bottle if it is good and hold pressure up to 150Mpa then that isn't the problem.