nor11384

iTrader: (1)

So about a month ago i ordered a walbro 255 pump. I have an evo 8. My old pump was also a walbro 255 and one day it started making a very loud whining noise which you could hear from outide the car very loud. The pump was usually pretty quiet. This is why i ordered the new pump. Today i went for a cruise with friends and after driving the car for about an hour i stopped and the new pump was now making that same noise. I noticed that when the pump was making this noise the afr went from 14.7 - 15 which is the normal to 16.5 - 17. I let the car sit for a while and when i turned it on again it sounded normal, wasnt making the loud whine. The afrs were back to normal. I sent the vendor (whos on here) an email explaining the issue hoping the will warranty it or something. Ive searched and read threads where people say theres alot of knock off on the market. Some people say the whine is normal some say its not. I dont think its normal, specially since when it was doing it the afrs went leaner. I just dont understand why is it doing it so soon. Pump has maybe 200 miles on it. My car is a garage queen and only goes out some weekends like today to go for a cruise with friends etc. What do you guys think? Should i think about a different pump? I tried to stay with the same pump so i dont have to retune. Car is just fbo making 380whp on pump.

hutch959

iTrader: (18)

you know what kind of fuel pressure you are getting at the rail?

nor11384

iTrader: (1)

I dont...i have an aem fuel rail which i put a gauge into the npt port...i guess i can check at idle...but its too much of a coincidence that the afrs went lean when the pump was whining loud as heck then went back to normal reading when it sounded ok...

hutch959

iTrader: (18)

i had one start whining once.... was a double pumper.

pulled the pump and one pump looked gold colored like it had been hot, other looked normal.
replaced the gold looking one....
problem went away.

probably a bad pump.

nor11384

iTrader: (1)

its a brand new pump...i hope the vendor is willing to warranty it but i get a feeling they wont on something like this...it sux because i just spent $100 on it...i read something about people rewiring the pump on these cars. Why do people do that and what are the benefits?

nor11384

iTrader: (1)

any ideas?

Biggiesacks

A propoer rewire wont effect your off boost fueling. The reason people do a rewire is because larger pumps draw more current, which because of the resistance of the factory wiring causes a voltage drop (ohm's law). The performance of these pumps is directly related to voltage. To reduce resistance additional wiring is added. The reason i said it wont effect idle is because at low load the ecu actually adds additional resistance to the circuit to lower power to the pump to increase the life of the pump and also to prevent regulator over run. This function needs to be preserved for the car to run right and to not burn up your pump.

nor11384

iTrader: (1)

Well, if this is the case why would i need a rewire with a walbro 255? Car has always ran well with it and afrs are on point even at wot. I usually get 11.2 - 11.4 at wot. My issue is this stupid pump changing pitch in whine. From barely audible to sounding like a jet plane. Wouldnt this be an issue with the pump? Thing is pump is brand new from a reputable shop on here. Is there a better plug n play pump I can try? Maybe aem or dw? Have you guys had better experiences with those?

Biggiesacks

Well they are notoriously called winebros. Mine can get pretty loud sometimes. Nothing alarming though, and since everyones noise threshold is different its hard to say without hearing it if yours is within "normal" levels for the pump. As far as why you would need to rewire, the 255 does benefit from a rewire at high load, but if you arent having fueling issues at wot then there is probably nothing for you to gain from it.

nor11384

iTrader: (1)

This thing gets loud...something like this...https://www.youtube.com/watch?v=Vi5MrBJvFSQ...now keep in mind this pump is about a month old...ive read that they get loud after hard driving or on a hot day which it was a hot day when it happened...im in florida so temps get up there...it was maybe close to 90 degrees out...i had a walbro in 3 cars before this one and none made this noise...i had an srt4 which left me stranded when the walbro died but it never made this noise either...idk...

Biggiesacks

well you replaced the pump to no result. Time to start looking for other potential issues. In housing filter clogged, FPR issues, Bad resistor pack...etc. Troubleshooting is all about eliminating potential failure points.

nor11384

iTrader: (1)

Yes id agree if i was having afr issues but the only time i saw the afr change at all was when the pump started making this noise...when car sat a while and pump went back to normal afrs were normal again so doesnt that point at a pump issue? Also, this rewire supposedly keeps the pump working in "high voltage" mode or "high speed" or whatever you want to call it. Doesnt that put more strain on the pump?

Biggiesacks

Check what i said in post #7. A proper rewire will only activate under boost. The chances of a new pump having the exact same problem as the one you just replaced seem pretty low to me. Not impossible, but i wouldn't waste a customers time/money just throwing more pumps at the problem.

nor11384

iTrader: (1)

ok, so i guess the rewire is the way to go right now right?

Biggiesacks

Rewire is kind of a bad term. Technically its more of an augmentation, because you don't actually remove the factory wiring, you just add a new circuit to it. It certainly wouldn't hurt to add the additional circuit. The additional grounding may help. As i said though, it should only kick on when under boost, so since your fault condition only happens at idle, I wouldn't be over optimistic about this solving your issue. I would suggest taking a look at the fuel pump resistor under the hood, as i have seen these go bad, to eliminate it as a possible trouble point.