shanex25

iTrader: (3)

So for a little background info, I've got a 1972 el camino with a 1998 camaro ls1/4l60e swap. I'm using the stock el camino gas tank with a sump installed on the bottom. I'm using all 6an push loc fuel line with Russell 6an fittings. I have a walbro 255 plumbed from the sump to a 99 corvette regulator that runs to the rail, and also has the return ran back to the sump. I finally finished my swap and drove the car for a half hour or so and the fuel pump started whining really loud, I lost fuel pressure and the car died. I've taken the pump and regulator off and plumbed it up on my shop floor hooked up to a battery and the pump runs fine, when I restricted the regulator I thought it was stopped up because it wouldnt blow any fuel out of the return. So my thought was that the regulator was stopped up and when the pump built up to much pressure it would start whining and quit flowing. Well I bought a new ac delco corvette regulator/filter and tried that. The car ran great for about an hour then the pump started doing the same thing. The weird thing is when I let it all sit for awhile I can go start the car and it will idle all day long with constant 55 psi of fuel pressure at the rail. If I drive around the yard the pump will get loud and it will quit again. I don't even have the gas cap on the tank so venting is not an issue. I have over half a tank of clean gas in the tank, the fuel pump is wired correctly through a relay by the signal from the pcm and I've tried two different brand new regulators. I've checked the voltage at the pump and I have 12.7v when the car is running. The pump also gets pretty warm when it starts whining. Here is a linked to my build thread if you want to see exactly what my set up is. https://ls1tech.com/forums/conversions-hybrids/1631831-1972-el-camino-ls1-swap.html
It's got to be a bad pump right? Just weird cause it runs good, cool, and quiet on the shop floor all day. Even when restricted through the regulator.