Rewired Walbro 255hp - constant whine?

[thekellbeast]

I know everyone's at the shootout this weekend, but I was still hoping to get a quick answer. I rewired my fuel pump a while back, and yesterday I installed a Walbro 255 HP. Just sitting there are idle, I could hear the whine changing pitch and getting louder/quieter. The interior lights were also dimming a little bit, and the car was running pretty rough.

Now, I'm going to blame most of this on not having an aftermarket AFPR. I know, I know, I should have one. But the car is just sitting in the parking lot doing a whole lot of nothing, so it's not hurting anything. I'm going to install one before it gets back on the road.

When I did the rewire I put a voltmeter on it, and was getting 14v. I'll be going back and doing that again with it idling, but I won't be able to get to the car for a few weeks. In the meantime, I was just wondering if it was normal for the noise to fluctuate at all, or if it should just be a constant whine. I don't mind it, I just want to know if its normal, and if my pump is pushing all the fuel it can.

Thanks.

 

[No_Skillz]

Should be a constant wine. How is your battery and/or alternator doing? If it's dropping in pitch, it's not getting enough power (sort of like unrewired, with blinkers on). Since your lights and stuff are dimming, I'm suspecting the power source, not your rewire job. It should have nothing to do with AFPRs... but you should get one.

 

[thekellbeast]

I did a bit more searching basically turned up with the same results you just said. I'm gonna try cleaning off my battery terminal posts. I remember the ground/neg being a little bit corroded. I'll try wire brushing that off and see what happens.

I also wanted to add (if it helps anything) that my tank is at a 1/4, and I did NOT install that little foam sleeve over the pump. It wouldn't have made any difference on the install, and the noise didn't occur to me when I had everything apart.

 

[No_Skillz]

Little foam sleeve little foam sleeve............

 

[MrBoxx]

Mike, some pumps come with a little foam insulating sleeve. It MAY cut down on the noise, but I doubt it. Walbro pumps are notorious for whining, re-wired or not. Eventually, you'll tune it out and you won't hear it anymore.

 

[No_Skillz]

I didn't get no foam sleeve with mine. I demand partial refund! Although I've begun to ignore the whine, I still have a hard time tuning out my girlfriend and sister and mom. Maybe I can use it and wrap it aroun their heads or something.

 

[thekellbeast]

If you want mine I'll mail it to you in an envelope. I don't feel like pulling the fuel line and opening the tank again, just for a little bit of noise. Hah.... funny how I'll put up with 'eeeeeeeeeeeeeeee' to not have to work on the fuel tank.

 

[interrupt13]

personally i like the whine of a fuel pump it lets others know you mean business. no ricer gets a loud fuel pump, they're too concerned with other things like neons to really care. I can spot a performance car a mile away by the fuel pump whine. i love it

 

[thekellbeast]

I can spot a performance car a mile away by the fuel pump whine. i love it

As if the 3" open turbo back exhaust didn't give it away already.I don't mind the fuel pump sound, I'm just trying to clear up the wierd power fluctuations and changing tone/volume of the whine. I may take a trip into work this evening to fix it. I'll report back with the results.

 

[thekellbeast]

I was feeling sort of bored in the house so I drove over to work to check on the Talon. The battery terminal was corroded to shit, so I cleaned it up and it solved the problem. The only thing is that the pump doesn't whine anymore at all. It does a little with the rear seat removed and the access cover off, but with both in place, I can't hear anything at all.

I put a multimeter on the outlets of the relay. The pump is getting a constant 14.1 volts at idle now. The weird thing is, when I rev it up hard, the voltage stays at 14.1 until I let off and then it drops to about 13.2, then comes back up as the RPM's even out at idle. What's the deal with that? It feels like it bogs down a little then - I mean, worse than it should as I let off the throttle. I thought the bogging might be because the stock FPR is being overrun, but the pump voltage is also dropping at the same time, which means it's flowing less fuel. Wierd.

Hmm..... Is the drop in voltage because the alternator is spinning down as the RPM's drop too? Just a theory.

 

[My91TalonTSi]

Although I've begun to ignore the whine, I still have a hard time tuning out my girlfriend and sister and mom.

It just takes practice, that's all I've gotten quite good at it.

As for my 255hp, it whines and changes pitch with the blinkers on. I don't have it rewired, but do have a new battery and alternator.

 

[No_Skillz]

The only thing is that the pump doesn't whine anymore at all. It does a little with the rear seat removed and the access cover off, but with both in place, I can't hear anything at all.

I've noticed that sometimes at first startup the fuel pump will not whine as loudly as after the car as warmed up. Perhaps less vacuum, more backpressure from the afpr, and therefore less fuel going through it?

As for my 255hp, it whines and changes pitch with the blinkers on. I don't have it rewired, but do have a new battery and alternator.

Mine does that too. I have a rewire kit sitting on my desk at home. If only I weren't in China.

 

[Locke]

I put a multimeter on the outlets of the relay. The pump is getting a constant 14.1 volts at idle now. The weird thing is, when I rev it up hard, the voltage stays at 14.1 until I let off and then it drops to about 13.2, then comes back up as the RPM's even out at idle. What's the deal with that? It feels like it bogs down a little then - I mean, worse than it should as I let off the throttle. I thought the bogging might be because the stock FPR is being overrun, but the pump voltage is also dropping at the same time, which means it's flowing less fuel. Wierd.

Hmm..... Is the drop in voltage because the alternator is spinning down as the RPM's drop too? Just a theory.

Hysteresis.

 

[Black_Bullet]

I was feeling sort of bored in the house so I drove over to work to check on the Talon. The battery terminal was corroded to shit, so I cleaned it up and it solved the problem. The only thing is that the pump doesn't whine anymore at all. It does a little with the rear seat removed and the access cover off, but with both in place, I can't hear anything at all.

I put a multimeter on the outlets of the relay. The pump is getting a constant 14.1 volts at idle now. The weird thing is, when I rev it up hard, the voltage stays at 14.1 until I let off and then it drops to about 13.2, then comes back up as the RPM's even out at idle. What's the deal with that? It feels like it bogs down a little then - I mean, worse than it should as I let off the throttle. I thought the bogging might be because the stock FPR is being overrun, but the pump voltage is also dropping at the same time, which means it's flowing less fuel. Wierd.

Hmm..... Is the drop in voltage because the alternator is spinning down as the RPM's drop too? Just a theory.

Yea if your rpms are dropping a little low before picking themselves up to the correct idle the alternator slows down a little bit and gives you less voltage.
Mine does that too, its set at 900 rpm idle and it falls to 500 then goes back up to 900 when im coming to a stop or if i rev it and let the revs come down by thereself. Its like it wants to cut off and has cut off on me a few times. I believe its another problem though with the isc or due to my lightweight flywheel...

I have a high pressure rewired walbro 255lph and man that pump was LOUD...
Like more than I could stand, Id have to always be playing music because it sounded like a huge mosquito in your ear... Then i decieded to remove the pump to make sure everything is ok with it since I thought it was louder than it was suppose to be and
i took the pump out completely examined it reinstalled it and voila it was quiet...? Maybe i had something tightened down too much and it was pinching the fuel connection on the top of the pump, idk but now the gas gauge doesnt work ever since i removed/reinstalled the fp I made a thread about it if anyone cares to help because im not trying to thread jack-

http://www.dsmtuners.com/forums/showthread.php?t=268316

But what im trying to figure out is if my noise level changing and getting quiet is relevant to the ops noise level getting quiet as well?

 

[lookin4dsm]

As for my 255hp, it whines and changes pitch with the blinkers on. I don't have it rewired, but do have a new battery and alternator.

My son's GST did the same thing. We just did the rewire the other day and the pitch no longer changes when the blinkers are on. Fairly cheap and easy mod to do.

Mike

 

[My91TalonTSi]

My son's GST did the same thing. We just did the rewire the other day and the pitch no longer changes when the blinkers are on. Fairly cheap and easy mod to do.

Mike

It's definitely something I want and need to do, but our shop has been so busy the past 2 months we just haven't gotten around to it.