Walbro 255HP fuel pump, couple questions...

[HaynStang]

So I just completed the install of my Walbro 255HP pump (thanks Stangnet!). The car starts and idles smooth.

I noticed a couple things different from my old fuel pump though and thought I would ask to make sure they're normal... first of all the pump is a lot louder at idle. It's noticeable while standing outside of the car. Is that normal for this pump? I realize it's flowing much more fuel than the old one did but I hadn't heard any mention of it being louder. I only have 3 gallons in the tank right now so in about 15 minutes I'll see if putting more gas in makes any difference.

Secondly, when I stab the gas with the car not in gear I'm hearing a "pssst" sound from the engine. It almost sounds like the blow off valve on a turbo car. It seems to be coming from my upper intake area... my fuel regulator directing back unneeded gas back to the tank, I bet? It's the stock regulator... is it normal to be hearing this sound?

On an off note it seems like the fuel pump may have been replaced before... the dead one I took out was a Carter... I thought all Mustangs came with Walbros from the factory?

 

[jcw88]

i have replaced my fp 2 weeks ago and as far as being louder not sure. the pssst noise is not from the fp might want to pull some codes or check the bladder in your fp regulator? and as far as brand goes most if not all fp's are made from walboro. i had a areomotive before and it was alittle different but i checked all other fuel pumps at the shop and they looked all the same. w/ the walboro engraved?? but mine works great..

 

[5spd GT]

Subscribing...

 

[Flavadave4]

I do believe the stock 155lph is a Walbro Unit. The new one is probably louder than the stock one, especially if the tank is near empty. The Fuel Pressure regulator is regulated by vaccum, maybe you have a split hose or somthing that is making the hissing? There is a vac line that runs into the top of the regulator.

Did you replace the regulator or take it off while installing the new pump?
You may want to think about an adjustable regulator and gauge to dial in the fuel system.

 

[cenok is family]

the walbro 255 pump in my old coupe was loud, you could hear it when idling. it had a quiet exhaust on it though. i just put a walbro 255 in my current car about a week ago and after i installed it, i stood near the rear to see if i could hear it and i couldnt. i have a pretty loud exhaust setup on this car though. i DID notice, however, that just the pump change up-ed my fuel pressure 5-6 psi and made my car fall on it's face at WOT. i had to turn my pressure down to like 30psi. runs great now. the injectors and pump are a little big for my setup but i figured buy now and save later. i got a great deal on both of them.

 

[strtrcr50]

I can barely hear my walbro gss340 when I turn the key to on before I start the motor. When started, I can't hear it at all..

 

[Flavadave4]

Mine make a buzz/whine sound, kind of faint but you can definatly hear it.

 

[5spd GT]

The level of exhaust and blower noise can also mask an ever-present sound...

 

[Grn92LX]

My 255 high pressure isn't loud either.

 

[HaynStang]

Weird... it has quieted down a bit now that I have a half tank of gas, but I can still hear it. It's a faint high pitched whine. I can hear it when sitting inside the car with the engine idling too. If anything it's slightly louder inside the car.

My old fuel pump had some type of cylindrical shaped foam rubber insulator around it that isolated the pump from the bracket. I wasn't supposed to reuse that, was I?

I debated about putting it on with the new pump but decided not to since it wasn't mentioned in Walbro's instructions or in anything I read online. Plus the install kit with the new pump was so complete I figured they would have included one if it was needed.

I'll have to inspect the vaccum lines and see if I find any leaks. It's the stock regulator and I've never removed it before.

 

[cenok is family]

Weird... it has quieted down a bit now that I have a half tank of gas, but I can still hear it. It's a faint high pitched whine. I can hear it when sitting inside the car with the engine idling too. If anything it's slightly louder inside the car.

My old fuel pump had some type of cylindrical shaped foam rubber insulator around it that isolated the pump from the bracket. I wasn't supposed to reuse that, was I?

I debated about putting it on with the new pump but decided not to since it wasn't mentioned in Walbro's instructions or in anything I read online. Plus the install kit with the new pump was so complete I figured they would have included one if it was needed.

I'll have to inspect the vaccum lines and see if I find any leaks. It's the stock regulator and I've never removed it before.

i bought this kit from latemodel when i put my pump in. it was only 12.95:

are you talking about the black rubber thing that goes around the pick-up part of the pump and goes between the pump and the bracket? i don't see why you'd HAVE to have it, but i would have reused it if i didn't get a new one.

 

[5spd GT]

I think he is talking about the gasket with the squared ends If so, that should either be reused or replaced...

 

[HaynStang]

I got that same kit with my Walbro...

I put that gasket with the square ends in... the one I'm talking about was like a foam rubber cylinder shaped "sock" that went around the entire pump to isolate it from the bracket... I'll see if I can post a picture in a moment.