problems with fuel system

[jshouse]

here is what i am running: fuel cell, walbro inline 255lph, corvette filter. last week i found some water in my gas tank after the truck started running real bad after it warmed up. it would fall all over itself under acceleration after a fwe minutes of driving.

i replaced the fuel filter, and found that when the truck started to run rough, it was because the fuel pressure was dropping to around 20. it would idle right at 60, then during acceleration, would fall to around 20, even from stop sign to stop sign in the neighborhood.

my buddy that tuned it thought that running the water through the pump had burned it up do to the water hindering the gas's lubricating ability.

so, yesterday, i replace the pump.

start it up, drive it around a bit, and after warming up, it starts bogging during moderate to heavy acceleration.

get home and put the fuel pressure gauge on it, and the damn thing is idling at almost 100psi so i havent driven it since.

i was under the impression that the corvette fuel filter was internally regulating. my buddy that did the tune doesnt think so, and says i need to put a hi-pressure fuel regulator on the system.

am i wrong about this filter and need to put a regulator on it? i thought after reading all of the conversion threads that this filter regulated at 58psi.

and would having TOO MUCH pressure cause it to act almost like it did when it wasnt getting enough?

i am about ready to just throw a carb on this thing

[RedHeartbeat]

The filter should regulate your pressure at 58 psi. Any excess should should be bled back into the tank unless something is blocking the ability to bleed the pressure back into the tank. Check your return line for blockage. You have the fuel pump hooked into the 3/8" side of the regulator, correct?

[jshouse]

i am about to leave work and will double check when i get home, but i am pretty sure it is.

i mean, it was staying at 58-60 yesterday, and i didnt touch the filter when i installed the pump. the filter is hooked up the same.

but i will look in a few minutes.

[jshouse]

the line from the pump is going to the inlet on the filter that is on the side, not the inlet right in the middle of the filter.

and i took the gauge off, put it back on, checked the pressure again. when i turn the key to the on position, and the pump primes, it goes to 80psi.

when i start the truck, it goes to 98 and stay there as it idles.

i do not understand. it was keeping it at 58 with the old pump, why not now.

is there any possible way of hooking the pump up wrong and causing this? if there is, then i could do it.

[RedHeartbeat]

Okay, the pump is feeding fuel to the inlet on the end of the fuel filter that has two fittings on one end and it is the larger of the two connections? The smaller one next to it is returning back to the fuel cell? The other end of the filter only has one 3/8" line going up to the engine?

[jshouse]

yes, the pump is feeding the larger of the two inlets. the smaller one goes back to the fuel cell. and the other end of the filter, with the one outlet, is going to the fuel rail.

[RedHeartbeat]

Check the return line and see if the pressure isn't bleeding back into the fuel cell for some reason. Sounds like something isn't working correctly, fuel filter or blockage in the return lines. Didn't you replace the filter recently? Do you have the old filter to try so you can see if you have a defective filter?

[jshouse]

yes, i replaced the filter before i replaced the pump. i will throw the old filter on today and see what happens.

thanks

[jshouse]

well, i took the return line off the back of the filter, and yes its hillbilly, but i blew into the return line and could hear the fuel in the cell bubbling.

so then i leave the return line off, and turn the ignition to "ON" and when the pump primes, it fluctuates betwen 50 and 60psi. not up to the 80 that it would prime at last night.

so not sure of there was something clogging the return line, or possibly clogging the return outlet on the filter, but i am going to hook the return back up and start it when all the gas dries up.

this is still with the new filter too.

[jshouse]

hook everything back up, prime the pump, primes right at 60, happy.

start it, and immediately it goes to 100+ and stays there as it idles, pissed.

gonna put the old filter on next and see what that will do.