Installed a walboro 255 fuel pump, removed 3 hoses to drop the tank, 1 being the filler tube, and replaced all the clamps with new ones, no leaks and wiring is right (doesn't do anything reverse-wired).

It turns on and tries to prime at 2nd ignition like it should, but it won't start pumping, i dropped the tank slightly and left everything hooked up and tilted the tank torwards the pump and primed it and heard it pushing through the lines and it started, put the tank back up, put some more gas in it, and again, heard the pump push on first prime, next two it lost pressure and wouldn't start again.

I've checked all the hoses and see/feel no kinks, wiring was soldered and heat-shrunk...i don't really see how it would be the pump itself, but at this point i'm assuming something funky is up with it, anybody have any ideas as to the cause of this?

Only problem i encountered during the swap was that the ceramic? piece over the positive wiring on the pump cap busted up during removal, wiring is still fine and siliconed over it. Other than that the pump is smaller but filter, while smaller in length, still sits in the same place, and see no reason it's not working....

 

To be precise, dropped tank once with about 1 gal, fired up, put tank up, nothing. Dropped again, fired up, put back up, put in about 4 gal, nothing. So amount of gas doesn't seem to matter because it should have gas over the filter as it is. But why would it start while dropped but not up?

 

wow....nobody?

 

okay, not sure if anyone cares...but here's an update...

i dropped the tank again, with about 4 gal in it...getting it back up is gonna suck, but anyways...it didn't start again, first time it's been down and didn't start, tried a few times and it wouldn't prime, pump runs, but no prime. So i disconnected the feed line at the engine bay filter and tried priming, gas pumped out on 3rd prime attempt. Hooked it back up and the car started right up. At this point i'm almost afraid to put the tank back up though...mainly...i don't understand why it would have primed and started before without being bled, and why it would need to be now, even though there's more gas. I could only assume more gas would equal out the pressure difference and be more likely to pump vs a half gallon. Maybe i'm wrong? Or maybe it was trying to put too much fuel pressure vs the existing line pressure and couldn't push past once filled? My main question to anyone who wants to take the time....is there ANY reason the pump shouldn't still prime and push gas once i raise the tank? I could understand if pinched lines, but all seemed fine and haven't moved from factory positions.

 

You waited a few hours for a response... People don't live on here.

What I have seen is the aftermarket sock "neck" is too long and pushes down on the "slosh box". This restricts suction on the pump and causes your described symptom. Look at a OEM sock versus the aftermarket one. You will see what I mean.

 

Yes...i realize, but it's a problem i need fixed asap..

I assume you mean the tubing from the pump to the pump cap as "neck"?
I trimmed the tubing to length to where it leaves the new pump in the same location. What's the "slosh box"? I've been through all the parts themselves, but don't know what all of them actually are called.

I kept on having problems and finally bled the system and it idled in my garage for probably 15-20 minutes..decided it should be fine to drive, got going just fine, but 30 yards down the street it died. I re-bled it in the middle of the road and my wife drove it back to the house. Tried again, same story...it's steadily pumping to the bay filter, but not firing up. I have been through my tps time and time again, but wonder if it's maybe not reverse wired and flooding it out or something? Being a huge pain in the ***. Idled okay but a bit rich, pulled away fine, sounded no different from normal, then just acted like it either didn't get any gas or way too much (instant stall)

 

he was referring to the "sock" filter at the bottom of the pump. i have been told that sometimes the sock filter sits too low and is pressed into the bottom of the tank, or that it is too short and doesnt sit low enough.

 

I was talking about the fuel sock. You should NEVER have to bleed the fuel system... Pull out the fuel hanger and replace the sock with OEM - I would bet that's the problem. Either that or you have a major clog or kinked line.

 

oh..yeah it sits just maybe 1 mm higher than the oem, but still gets gas to the filter so it's covering. biggest difference i noticed on the filter is that it's just way shorter, and the oem had a little bend probably dipping into the deeper parts, but even on a hill it's pumping to the engine bay filter, so that part of it should be within spec, no?

 

yeah i couldn't understand why i would've had to bleed a mpfi system, not normal...if it's pushing/priming to the bay filter wouldn't the clog/kink be more likely to be after that point though? I'm kinda in wtf mode so you'll have to excuse me. What about the tps? This wouldn't kill it from being over-rich or going lean after idle?

 

If its higher it shouldn't be a problem if it's covered by fuel. I was referring to the ones that are too long. I would be concerned with you breaking off that piece of the pump. Check your voltage to the pump and see if there is a loss.

(I didn't fully read your first post for my first post...)

 

Yeah too long isn't an issue with this one, sits about right really, was kinda suprised. Shouldn't be any voltage loss from the oem, i cut the wiring under the cap and soldered/heatshrunk, only i know i should've trimmed the pump clip wiring to length, it's about 6" and loosely wrapped around the frame a couple times and clipped in. How do i go about checking the voltage though? I've replaced pumps before but never really diagnosed em, i would think though that it would need to be checked at wot and idle wouldn't it? To ensure voltage throughout?

 

i am having the same issue on my 94 accord. i installed a 255lph pump. i used the factory connection. i had to cut out a section of rotted fuel line and replace it. i know all the feed lines were empty. i used the oem sock on the new pump. i primed it a few times and got nothing. i removed the feed line from the fuel rail. i promes it 2-3 times and got nothing. then the last time i primed it i got some fuel. i reconnected the line and it ran fine. let it run for about 10 mins then shut down. when i went to restart it wouldent start again.