1G Fuel Pump Whine

[IceMan526]

I have a walbro 255 in my tank, it has the rewire. Ive been working on tuning off and on for a few months now and never heard this noise. Now whenever I start it up it starts up pretty quiet, about the amount of noise you would expect from a walbro and then it progressively gets louder. Within 5 minutes you can hear the thing across the street in the house whining.
Like I said it just started doing this recently, there are no differences in the idle or anything else, just the noise and I mean loud. I know some people say they like the whine but I believe they are talking about the subtle whine that comes with walbros not this deafening whine that is almost drowning out my exhaust.

 

[curt-s]

Are you able to measure the amperage the pump is drawing from the electrical system?

 

[IceMan526]

Im going to run to harbor freight right now and grab a volt meter. Ill be back shortly with results

 

[jbeaton9292]

Mine was pretty loud back there in my 1g

 

[curt-s]

Im going to run to harbor freight right now and grab a volt meter. Ill be back shortly with results

To measure amperage properly, you'd have to have the ammeter in-line from relay to fuel pump.

While volt meters usually have an amperage metering function, you have to ensure they are able to meter the amperage a fuel pump will draw -- this will likely be above 10A. Otherwise, you risk blowing the fuse in the meter or worse, if it doesn't have a fuse, starting a fire.

The reason I ask this is you can use the determined value to check if it's within the operating range known for the pump. If it's low or high, there is definitely an operational issue. This isn't the only way to figure out if you have a bad pump, but it's an indicator. I do not request you go out and buy a $60 (or higher) meter to do this test, but everybody should have a quality meter -- especially if you have a DSM/23 year old car.

Just FYI, in my 1G FWD, I can hear the pump from behind the vehicle.

 

[IceMan526]

Well the one I got from harbor freight only measures up to 10 amps, tired it anyways and it got hot fast Im going to run to the shop because I think there is a better meter there.

Mine was pretty loud back there in my 1g

Could you hear it from inside your house while it was parked across the street running, so loud it drowned out my 4" turbo back exhaust

But anyways its got good voltage back there and ill grab the other meter so i can measure the amps

 

[jbeaton9292]

Well the one I got from harbor freight only measures up to 10 amps, tired it anyways and it got hot fast Im going to run to the shop because I think there is a better meter there.



Could you hear it from inside your house while it was parked across the street running, so loud it drowned out my 4" turbo back exhaust

But anyways its got good voltage back there and ill grab the other meter so i can measure the amps

dang mine wasnt that loud but could hear it inside the car with o2 dump on my hx35

 

[IceMan526]

dang mine wasnt that loud but could hear it inside the car with o2 dump on my hx35

ya its freaking loud

I went and got the other multi meter which is alot better than the cheapy from harbor freight but it still has a 10 amp max or 400 mA max. and 4mA is only .4 amps so how would a normal person without a bunch of fancy tools measure amps?

I found this chart
http://www.roadraceengineering.com/fuelpumpflowrates.htm

if you look the only times the amps should be above 10 is when the fuel pressure is REALLY high. The base fuel pressure Im running at idle is 37.5 psi so there should be no reason its above 10

 

[curt-s]

Are you absolutely certain it's your fuel pump that's making the sound?

Other question, do you have the ability to log fuel pressure? If you see a 1:1 rise in pressure on boost, and it's constant with no ugly fluctuations or swings (like the pump is unable to keep up), then I'm willing to bet that's just how it is. At least, in terms of being able to hear the sound from outside the car.

However, I really don't see how it could overpower a muffler in audible volume. The notion that you thought you could hear it in a house across the street while the car is running is quite unbelievable, to be perfectly honest. If it really was that bad, buy a new one and see what the volume of that one is.

 

[IceMan526]

Yes Im certain because the noise is coming from the tank and there is just nothing else it could be back there. Plus you can hear the pump when you start up the car and then hear it get increasingly louder so it definitely is the pump.

I do not have the ability to log fuel pressure.

Im honestly telling you it really is that loud. I know its hard to believe but it whines like nobodies business. Im just going to buy a new pump and throw it in there, its pretty easy and the pumps arnt that expensive so it wouldnt be too much of a hassle. After I get the pump and put it in Ill post on here if there is a change.

 

[wishihadatalon]

If you can, pull the pump out and take a look at the pre filter sock and also the condition inside of the tank. It could be possible that you have crud in your tank that limits the amount of fuel the pump can draw through the sock. I had a brand new 255 that got really loud in a car that had sat for a few years. Varnished gas and other crap ended up clogging the sock. Once I cleaned everything out, the pump went back to the normal faint wally whine.

 

[thomcasey]

Check your fuel filter and the conditions inside the tank (fuel sock). Either being dirty will cause that noise and it tries to keep the fuel flow up.

 

[curt-s]

Yes Im certain because the noise is coming from the tank and there is just nothing else it could be back there. Plus you can hear the pump when you start up the car and then hear it get increasingly louder so it definitely is the pump.

I do not have the ability to log fuel pressure.

Im honestly telling you it really is that loud. I know its hard to believe but it whines like nobodies business. Im just going to buy a new pump and throw it in there, its pretty easy and the pumps arnt that expensive so it wouldnt be too much of a hassle. After I get the pump and put it in Ill post on here if there is a change.

Alrighty, good luck!

 

[tmoney20g]

How old is it? You could have a bunch of crum on the pump strainer. Much like when you suck up the carpet with your vacuum, the vacuum goes apeshit and draws more power.

 

[crimsondragon]

ya its freaking loud

I went and got the other multi meter which is alot better than the cheapy from harbor freight but it still has a 10 amp max or 400 mA max. and 4mA is only .4 amps so how would a normal person without a bunch of fancy tools measure amps?

I found this chart
http://www.roadraceengineering.com/fuelpumpflowrates.htm

if you look the only times the amps should be above 10 is when the fuel pressure is REALLY high. The base fuel pressure Im running at idle is 37.5 psi so there should be no reason its above 10

I doubt that chart is accurate at all. I've blown a 25 amp fuse with a rewired Walbro 255 HP. Had to up it up to a 30A. I don't know any guide that recommends a fuse lower than 30A.