Fuel pump question.

Sites

Well-Known Member
After much at-home diagnostic work to figure out why my engine falls flat on its face during mid and full throttle, I think the issue is fuel pressure. Since I am running a fuel cell, I ditched the factory fuel pump and I am now running an inline pump that is capable of pushing 60PSI. When the truck is idling, it maintains the proper pressure in the fuel rail (30psi), but when I rev it up, instead of the pressure rising to 40-45psi, it drops below 30.

My question is, when running a return line into the tank, is it ok to dump it back in from the top of the tank at the fitting? Or is it necessary to run a line from the fitting inside the tank, down to the bottom so it is submerged? Someone just told me that this is necessary to maintain pressure in a fuel system that runs at such a high PSI.

Any comments?

Thanks,
Andy

94' Lightning Prerunner (money sink)
 

desertracer

Well-Known Member
From my personal experience it is ok to dump the fuel in from the top of the tank. We have a motec injection system in our car and we have a -6 line going into the top of our cell as a return for the injection system. We have an inline bosch pump that pumps through the fuel rail then to a regulartor then from there a return back to the tank.

MDR Class 1
#112
 

Dylan

Well-Known Member
THE PUMP MAY BE CAPABLE OF THAT KIND OF PRESSURE BUT NOT THE VOLUME NESSARY
ALSO IS THE FUEL PRESURE REGULATOR PLUMED TO THE RIGHT PRESSURE OR VACUME PORT?
 

Sites

Well-Known Member
Yes, the regulator is a new factory unit and is plumbed to the correct vacume port (no leaks).

94' Lightning Prerunner (money sink)
 

Sites

Well-Known Member
Not yet, I am going to tonight. I just installed a new filter a few months ago. Unless its getting clogged by debris from the fuel tank, I didn't think it would have already gone bad.

94' Lightning Prerunner (money sink)
 

hoeker

Well-Known Member
a proper system has the return submerged, this prevents the fuel from aerating. usually the return is also close to the pickup.

good luck

Some are born great, some achieve greatness,
and some have greatness thrust upon them.
 

Sites

Well-Known Member
Well, I figured out the problem. I pulled the pump off and the screen that resides on the inlet side of the pump was completely clogged with residue from the tank. I cleaned it out and now the truck runs great.

94' Lightning Prerunner (money sink)
 

Sites

Well-Known Member
Just having fun with it, even more fun now that the engine doesn't want to always die :) . I was out at the Fud race and then over to Ocotillo last Saturday. Bilstein set the coilovers up to run with a bypass shock, so they are VERY lightly valved. I have bypass shocks on order from Bilstein, and I am hoping to have them in the next few weeks. I am probably heading back out to either Ocotillo or Plaster City next Saturday w/ the truck -- Fantelli is going to be out there testing his new 8 truck.

- Andy

94' Lightning Prerunner (money sink)
 

Sites

Well-Known Member
Here are some pics right before we finished it back in March.







94' Lightning Prerunner (money sink)
 

Project1500

Well-Known Member
Wasnt this truck just currently put in the readez ridez withing the last month or so?

What can't kill you will only make you stronger
 
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