walbro 450
 

So i have a question for you guys. Im having some fuel pressure issues with a return style fuel system with a walbro 450. At key on the pump stays steady at 58 psi but when the truck goes under any load say up to 80-100 kpa it lses all fuel pressure down to 20psi. I back probed the wires at the pump and they maintain 13volts the entire time thoughout. So my question is do yall think the pump is bad or clogged? Any suggestions did i get a bad/fake pump?

How did you do the hose in the tank? Did you use submersible rated line or just typical fuel hose? I bet you have a leak or the hose is split there.

Used gates 3/8 submersible fuel line 30$ a foot lol and its no split i took it out yesterday to check everything is all intact

Filter clogged?

have a prefilter on pump that doesnt seemed clogged and a post 10 micron filter that i cleaned and its still doing it

Have you checked your lines for kinks ? I changed my fuel pump in my Typhoon back in the day and I found that someone previous to me had twisted and kinked the rigid line, it still ran OK on my truck, but I could definitely see an issue on a truck with higher demands.

Also, did you buy the pump from a reputable vendor? Possibly they sent you a mis-represented pump as a Walbro 450.

Just my $0.02

The lines in the tank are cut straight to the length of the fully collapsed position so i know that isnt kinked. All the other lines are AN lines to the rails and the stock feed line for the return line now. I bought my first pump on ebay so thought that was it so i bought another one from walbro and its doing the same thing still. THe pump will hold 90-100 psi at key on without the motor on

possible leaking regulator