So my fuel pump on our S, which has the greddy AP1 kit installed, started to howl and whine a couple of months ago. After a four month ordeal getting a cast iron manifold to replace our cracked tubular one, i decided to just have it replaced on my own dime. so i had the shop install the same model that had failed and all's well.

Then today, the whine from the pump is back. Is anyone else experiencing this? Is there something in the kit that is causing the pumps to prematurely fail?

thanks,

Kent

 

its normal.

i'd recommend you search before you just go replacing parts.

oh, and any shop that replaces an aftermarket fuel pump because "it whines" should be out of business.

 

From my experience the Walbro 255's whine most of the time. The whining tends to get louder as the tank empties. Mine may not be flwing quite enough fuel in the higher RPMs, because I tend to go lean after about 7K rpms and my tuner couldn't get it leaned out. Soonce I get my 70mm catback I am taking it back for a retune and he will have the proper tool to read fuel pressue on an S.
I have heard of several people having the lower fuel pressure at high rpms problem with the walbros, but the whine is pretty normal for these pumps. We are used to not hearing our fuel pumps at all, but say goodbye to that!

 

ok, but why would the pump run totally quiet for a YEAR, then start to howl. we're talking loud enough that i have to turn the stereo WAY up just to drown out the sound. then the second one runs for two months, absolutely quiet, then start to howl.

BTW, the shop is a good one.

 

howling comes from the level of fuel. mine seemed to get louder over time, maybe a 50% volume increase. but again, it depends on the level of fuel. right around 3/8 of a tank mine is LOUD. seems especially worse if you are still. (not moving)

if you are 100% certain this is not a typical howl-----

there really nothing that could go wrong with a pump that would allow it to run (normal) and make excessive noise.
in other words- if the noise is abnormally loud, you'll be seeing less performance from the pump.

also, fwiw- i've also never seen a walbro 255 get louder when something goes wrong. i've only seen rattles and seizing.

 

that's why this puzzles me. my tank is full and the sound just gets unbearable. most pumps i've seen either work or they don't, but never scream like this. you can hear it clearly from outside the car as well

we've got other cars in the shop with walbro 255's and they don't make this sound.

 

the pump sounds more like a hydraulic ram motor on those trucks that can lower a platform than a fuel pump

 

yeah. my 255 sounds like that if i sit in a parking lot with the car running.. with 3/8 of tank or so.

 

like the others said its normal. mine whines loudly outside the car, inside the car, standing on top of the car, doing cartwheels around the car...

 

do you see your voltage level go down when it starts to whine? Could it possibly be drawing a larger amount of amps and its not getting enough juice? Some sort wiring issue?