Walbro 255hp failure?

[kamronman]

My fuel pump either failed or the hose popped off yesterday from pump to feedline..I don't get over cruising fuel pressure!

For about a month i've been hearing a loud whistling or moaning sound from the back of the car when accelerating normally and only at a certain rpm does this whistle starts to build up sounding like a turbo spool but obviously not. So i figured it must have been the wind against the vents on the side of the car, or one of my many vacuum leaks making the noise.

So before doing a 3rd gear pull on the freeway yesterday the noise was so insanely abundant and loud but i was ignoring it, then as i WOT nothing was happening but the noise in the back got louder . Fuel pressure wasn't going past 40psi, and i'm running 26psi of boost usually(but rpm was barely going up, no boost was building). After that try the fuel pump kept making noise and i stayed under 20% throttle the whole way home.

Did my fuel pump fail? Because i've known them to either work or not work..not slowly die out. So i figure it's overworking back there because maybe it's leaking fuel back into the tank. please help me out guys, i wanna save the 90$ it will cost for a new pump

 

[95blackGsTurbo]

Take the pump out and check it. Sounds like the sock may be plugged and starving the pump.

 

[90moneypit]

Take the pump out and check it. Sounds like the sock may be plugged and starving the pump.

+1 with the added provision that if it's not, you check your fuel filter and lines for blockage. Also, if the sock is dirty, you might want to drop the tank and clean all the sediment out of it or it'll just happen again.

 

[kamronman]

I drained the tank and took the pump out to inspect it, the sock appeared to be just fine, it barely had an orange tint to it and there was no sediment stuck to it. I also blew out my other fuel filter and it's just fine! I put everything back together today with the stock regulator just to test my aem one, and the same symptoms are happening!! No more than 43psi of fuel pressure, and when it tries to go beyond, nothing happens...no boost, loud noise from the back of the car. And another clue, is when i shut the car off i hear a draining/creeking sound slowly fade away in the back of the car seconds after the engine is off! And remember i have no interior so it's easy to hear these sounds. Please keep giving me suggestions! thanks


Edit: After hitting google with my problem i found a few possible causes for my fuel pump failure, so tell me what you think.

1. Fuel pump is vibrating ( I didn't use any zip ties or anything to hold it tight to the bracket that holds it, how would vibration cause it to not pump?)

2. Overheating pump ( I read that the walbro's use gas for cooling, and my car has never seen more than a half tank before, usually being driven on a quarter tank or near empty[i know this is careless and not smart])

 

[Redwidow]

The Overheating of the pump shouldnt have anything to do with it, and all in tank pumps are cooled by the gas that surrounds them. Granted this is no stock pump, but I still cant imagine that running it on only 1/4 tank would ruin it. If it was prolongued exposure and constantly running it at less than 1/4 tank or on E all the time, then possibly, but not likely. Do you still have the stock pump? If so have you tried putting that in and running stock boost? I would try this and see if the symptoms go away.

 

[kamronman]

Thanks! but i just pulled the walbro AGAIN, and this is what i found, which supports all the symptoms i was getting!

<a target='_blank' title='ImageShack - Image And Video Hosting' href='http://img189.imageshack.us/i/0417001949a.jpg/'><img src='http://img189.imageshack.us/img189/7596/0417001949a.jpg' border='0'/></a>

I'm still researching what this is, but i think i've heard of it being a pressure release valve or something. But right there to the right of the output i can see all the way inside the dang pump from that hole! and the sound from the back i was getting sounded like fuel spraying the inside of the tank from the return line, but i found another pressurized hole please tell me how to fix this!

Edit: Ok after looking at another walbro 255hp i found that the hole is supposed to be there..but i went ahead and put the other walbro pump in my car(a known working one) so i can find out if it was my pump tomorrow. I'll have to put my aem regulator back in and reset my globals on link.

I put a new walbro 255hp in and same problem!! I'm starting to think this is an electrical problem..is the signal to the pump not getting to the pump? Does anyone know where the signal comes from and where to check to see if it's being interrupted? Please get back to me asap




EDIT: Pulled off my intake pipe, blown turbo.