racerx520

iTrader: (1)

Hey guys, I'm currently running a walbro 255 pump but after 1 month it won't hold pressure when I turn off the car. I'm gonna have to drop the tank and replace it. I don't think I'm going to risk using this brand again. I read a post on ls1tech saying there are a bunch of China made walbro pumps that are of lesser value but cannot be differentiated online since they look identical down to the walbro name on there

I saw on summit an edelbrock pump, do you guys think that is a good brand?

8t2 z-chev

I installed a Delphi pump in a '93 f150 and it has been good for a year now-was made in USA,but I don't know about Delphi pumps meant for 3rd gens.The original ford pump was made by Walbro and lasted 320,000 miles,though this is a dual tank truck so many of those miles were on the other pump that also quit and was replaced...

racerx520

iTrader: (1)

I've always heard stories of how the dual tank pumps were always unreliable. And if they were walbro I feel like that's not helping the trust issue I now have with them

On the ls1 forum they recommended a racetronix pump. Dont know where I'd find one of those, it's not listed on summit and i prefer to go through a company like them. Got my walbro pump from amazon and I don't think I'll do that again

Caveman305

iTrader: (8)

sorry to ask this, but I need more information before i respond

what have you done to narrow the issue down to the pump?

usually not holding pressure would mean leaking fuel injectors or a bad Fuel Pressure regulator

thtanner

iTrader: (1)

The ACDelco EP381 is a good fuel pump. It's a better design than the EP241/242 stock units.

I'm removing my Walbro 255 unit in favor of the EP381.

Just make sure it's the fuel pump causing your loss of pressure.

racerx520

iTrader: (1)

i had persistent fuel problems with this motor since building it, so i've replaced the injectors, the afpr and filter. the pressure then dropped and was jumping between 25-35psi rapidly and it didnt matter if i had the vacuum hose off or not. After a bunch of research i found out the pulsator was bad, so since i had to pull the tank i also replaced the sender, pump, sock, and filter.
I went to take it out of the garage and it wouldnt stay running again ,so i put a gauge on the rail and found it not going over 35 psi but then when the motor would die the pressure would drop immediately to 0. I did a leakdown test and found the following:

when clamping the return line only, the pressure would build to 35, then drop to 0 immediately

when clamping return, then build pressure and clamp the supply, the pressure stayed at 35. I released the return line and pressure held, so i released the supply and it went instantly to 0.

according to the leakdown test, this is indicative of the fuel pump not holding the pressure in the system.