pun young

Fuel pump will hold 60psi when the truck is idling, but when I rev it up an hold rpms will drop down to 20 or so psi, what could cause that or where should I start trying to fix it. I'm running.030 over 6.0 with 75mmturbo, aeromotive a1000, with pre and post filter, which look new still, with -8an feed and -6an off the rails to the regulator and -6an return, return flowing good back into the tank and vent is clear, also was running fine when parked.

JoeNova

Is your regulator vacuum/boost referenced?

stevieturbo

Are you talking about revving under load or just sitting still ?

pun young

yes it is


just sitting still, so only can assume loses pressure under load too

stevieturbo

presumably this is a new install and never been driven then ?

Something is clearly installed wrong or there is a burst line inside the tank or something

JoeNova

Unhook the vacuum reference from your regulator and check then.

pun young

It has been driven before, but broke the rear end, so after fixing that it started doing this. Didn't touch anything on the fuel system, just started doing this

Bob@BruteSpeed

iTrader: (16)

Even though you said return is flowing well, I'd check to make sure the insides of your fuel lines haven't degraded and become spongy. When this happens it normally shows up in your filters, I know you said they are clean but I'd start there. Bob