Dual fuel pumps pressure still drops

[chris89]

So I finally put dual stockers on and my fuel pressure still drops to 30psi from 65psi. One pump is wired from key on and the other is run off stock wiring. Still running stock suction and lines after the "T" if that makes any sense. Anything I can do to see if anything else is the problem?

 

[CSIPSD]

Have you dropped the tank?

 

[97powerstroke]

You need to run bigger fuel lines from the tank up to the motor including the pickup in the tank. Your not getting the fuel volume you need just by running dual stock pumps. You can put the biggest pump on you can find but if you still run the stock fuel lines you won't gain much. The only way you'll gain the volume is by putting all new fuel line on.

 

[CSIPSD]

With just 230's he really doesnt need anything... He needs to drop the tank and clean/remove the pick up screens.

 

[Dieselboy.]

With a 200% nozzle.... He needs bigger lines.

Op, grab one of those pinner little soda straws, 1/8 Dia. And drink as fast as you can.... Do the same with a slushy straw..... Same concept.

You may also need to run new wires to the pumps. Use your factory wires as the control and pull power from the battery and use 10-12g wire to get the full 14v to the pumps. For me the difference between 14v or 13.5v at the pumps was 67psi or 55psi

 

[KBMKVIII]

I made a new circuit to run my duals with relay and all.
And you should get a sump or a larger pickup at least.
Also a larger return and supply line.
But the first thing is to clean your pickup screen.
Ran my pumps at first through the stock pickup with no drop in fuel press.

 

[CSIPSD]

With a 200% nozzle.... He needs bigger lines.

Op, grab one of those pinner little soda straws, 1/8 Dia. And drink as fast as you can.... Do the same with a slushy straw..... Same concept.

You may also need to run new wires to the pumps. Use your factory wires as the control and pull power from the battery and use 10-12g wire to get the full 14v to the pumps. For me the difference between 14v or 13.5v at the pumps was 67psi or 55psi

No, the factory pick up will work fine, assuming the screens are not plugged...

Will it work better with a 5/8 pick up, sure, but it will work fine without it. Right now he has a restriction in the tank that is causing his issue.

 

[chris89]

No I haven't dropped my tank. I have a sump but not sure if I want that hanging down off the tank. Could I get away with running 1/2" line?

 

[neverkickn]

No I haven't dropped my tank. I have a sump but not sure if I want that hanging down off the tank. Could I get away with running 1/2" line?

Yes, but you would need to drop the tank to install that and it seems that you are unwilling to do so. If it makes it any easier, you can also remove the bed to access the fuel pickup.

 

[Groomzybanshee]

With a 200% nozzle.... He needs bigger lines.

Op, grab one of those pinner little soda straws, 1/8 Dia. And drink as fast as you can.... Do the same with a slushy straw..... Same concept.

You may also need to run new wires to the pumps. Use your factory wires as the control and pull power from the battery and use 10-12g wire to get the full 14v to the pumps. For me the difference between 14v or 13.5v at the pumps was 67psi or 55psi

Disagree I've ran 250s, 350s and even a set of 650s on a stock line 0 pressure drop. Yes I upgraded to a bigger one for the volume but still didn't have any pressure drop.

 

[chris89]

I'm just saying if I am dropping the tank I would rather make the lines a little bigger is all

 

[Groomzybanshee]

I'm just saying if I am dropping the tank I would rather make the lines a little bigger is all

Put a pick up tube in an run a bigger line from it to the pumps will tank is dropped. That's what I did.

 

[SDstroker]

Run 5/8" line from the tank to the first filter, 1/2" to the engine. I used stock return line. Holds everything I throw at it. Thats with a 5/8" straw.

 

[Dieselboy.]

Disagree I've ran 250s, 350s and even a set of 650s on a stock line 0 pressure drop. Yes I upgraded to a bigger one for the volume but still didn't have any pressure drop.

Might not have dropped pressure. But wouldn't flow the volume that bigger lines would.

You might also have a weak pump. I had that once and it would suck it down to 35psi

You need to drop the tank and run bigger lines.

 

[chris89]

Well had the tranny out today and was looking at the fuel lines, after my T fitting the hose was rolled over and kinked just a little. Now I just have to find time to rewire my 2nd pump.