Losing fuel pressure

[ecld_07]

Wanted to run this by you guys and get some ideas. This is a 2004 ext cab with 6.0, cam, headers, and so on. Was runing a bone stock fuel system for the last year with this setup. Literally overnight it started running like crap only at wot. Get a gauge on it and at wot it's falling to high 30s fuel psi...... Since then added 42lb injectors, walbro 255, new pressure regulator....no change..... Any one got any ideas???

[96/chevy/pu]

Bad fuel pump ground,or bad fuel pump relay? Only losing pressure @ WOT?

[ecld_07]

Only at wot or close to it. Other wise completely normal. Swapped relay around with another truck. Connections are clean and good.

[bootlife]

Fuel pump, I had that problem, check ur fuel preasure on the rail. Mine ran fine till u got on it. Changed pump good to go.

[ecld_07]

As stated...It did it with an oem pump and a new walbro 255..

[bootlife]

Check ur voltage at the pump see if ur getting the right power to it, if ur not getting the right fuel I'd start at the source I go from there.

[408Lbb]

If just put new pump in possible the line has split after install or leaking Also did u drill out bottom of bucket to alow more fuel in bucket for the higher flowing pump. If not it run out fuel at wot

[ecld_07]

Double checked all that

[96/chevy/pu]

Awesome suggestion didn't even think about that, kind of like the old Q-Jets running out of fuel in there small secondary capacitys

[bootlife]

I'm not trin to sound like a dick I'm trin to help, if ur getting correct voltage at the pump, ur loosing fuel at the rail, I assume u checked ur filter and for leaks, I'm sayin new or old ur pumps not puttin out, I'd pull the pump make sure it's not stops up first. Also there's a ground on pass firewall that gets loose n shuts off the relay to the pump