twin stock pumps not keeping up

[Rubyred]

I bought a used Irate basic fuel system with walboro gsl392 pump, after a few months it went out so I used my old stock pump with 160k miles on it and bought another new stock pump to run in parallel. since then the truck will not hold 65psi when in the pedal, even on stock tune. Ive tried replacing both filters, working all kinks or bends in suction side, pressure side doesn't have any signs of kinks im just stumped.
Tried plumbing one pump in at a time and each single pump would only make 42psi no mater what I did with regulator besides literaly just about dead heading it
Tried pressuring up the fuel tank through the fill cap 3-5psi to "push", the fuel to the pumps seemed like it would still go down when just reving it up a bit.

details on the system ive put together is from tank..... steel 5/8 pickup tube> 5/8 line to filter base>30mic water separator> 3/8 Y into pumps> 3/8 Y out of pumps into 6mic filter> 3/8 line up to back of heads and a Aeromotive regulator..... I spliced into existing factory power wires for one pump and ran separate power wires from battery with the help of a relay. truck has 230/100's

 

[joe d]

My dual setup never moves from 68 on my 238-100 same line sizes as you. Exsept where you have 3/8 i have 5/8

 

[Rubyred]

im just completely stumped as to what could be the problem here. sitting here thinking about it though it may be possible I cut that pickup tube too close to the bottom of that tank, cause with both pumps plumbed in, I can regulate it up to 70psi but as soon as I put the pedal down it will drop to 45-50psi

 

[joe d]

Did you have issues with the walboro?

 

[Magnum PD]

Did you cut the pick up tube flat?

 

[joe d]

Mines cut on an angel maybe a 45..

 

[Magnum PD]

Mine too.

 

[Rubyred]

I don't recall the walboro dropping like a rock like this dual setup. yes I did cut it flat I have the truck on a lift im about to drop tank and try cutting it at an angle that makes sense to do now that you mention it whoops

 

[Magnum PD]

Gotta feed the beast to make it roar.

 

[Rubyred]

oh believe me I know. I have a sled pull tomorrow I would like to participate in and I need all my horses in a row if I wanna compete with them tuned Dmax boys

 

[Magnum PD]

Don't expect to leave them in the dust.

 

[Arisley]

Instead of wiring like you have it, use the factory wiring to fire two relays. Use fresh battery power run through two fuses for the power feed through the relays. Each relay feeding one pump. I have my 5/8 draw straw cut on a 30º angle. I also notched it in four places. I am plumbing basically the same as you, except my filter bases have two feeds and two exits. On the pre-pump filter, I have one of the feeds plugged, on the post pump, I have one of the exits plugged. I am also running 5/8 inch line to the splitter and 3/8 inch from the splitter to each head. I run 1/4 inch from the heads to the regulator and use the factory 3/8 supply line for a return. I have my regulator set to idle at 65. At WOT, it will drop to 63. I ran it with one pump dead for about six months. Unless I went to WOT really fast, it would still hold 55 lbs.

It freaks gasser guys out when they see a fuel supply line as big as a garden hose. Really freaks them out when with normal everyday driving, I still get 17 MPG.

 

[pwrstrk01]

I had a similar problem I put a set of driven diesel banjo bolts in and haven't had a problem since

 

[Rubyred]

I ended up cutting the pick up tube @ a 45 and adjusted the regulator to 70psi and it would hold on a HOT tune to 60-65psi so i wasnt scared to run it. Im thinking im guna go back to another walboro or bigger bosch pump and sump setup


Sent from my iPhone using Tapatalk

 

[emev0l]

Try a Baldwin BF1252 pre-pump filter/water separator, it's a 40 micron filter. I know that one works for sure.

 

[mikeeg02]

Glad you got it fixed but.....

Didnt people used to have longevity issues with the walboro pumps? If you have two SD pumps, why would you change it? IMO there isnt a better setup for long term reliability. Most SD pumps last the 250k mile region, from what Ive seen.

 

[Magnum PD]

:whs:

 

[emev0l]

I killed 2 Walbro's within a year, they held pressure great until they died. This was with a full 3/8 fuel system from the tank to a pre-pump filter into a Walbro into a post pump filter into a RR. I've seen other trucks have the same issue, I don't recommend them.

A sump on the other hand never hurts, it's easier on the pump, gravity is better then suction.

 

[Rubyred]

Ya, i may stay with this dual setup if i can get all the kinks worked out. Still doesnt hold 65psi full throttle so ill try a sump and wire in the pumps like mentioned above


Sent from my iPhone using Tapatalk

 

[mikeeg02]

If you get rid of your stock pumps I'd be interested in them.