aem fuel pump emmits a hogh pitched sound

[hendrixgr]

aem fuel pump emmits a high pitched sound

Hi.
I just wanted all of you to know that i am changing my almost brand new (two months in operation) AEM 320 L/h in tank fuel pump to a Bosch 044 because last Friday it started making a high pitch sound that i could hear 10 feet away from the bike.
This sound went away after 1-2 minutes of warm up but Saturday it started reappearing in a more consistent manner until it became permanent and the engine also started to become increasingly difficult to start (needed 3-4 seconds of cranking) and that immediately sounded the alarm!
I don't know if the pump is dying because it is not well made or something else caused it like bad fuel or bad installation etc (something that i shall probably know Monday when i shall get the bike back), but i decided to go the Bosch 044 route just to be safe, something that i should have done from the start.
Tuesday i will post what i found and some photos.
Chris

 

[1bondoman]

Aem320 is a pain to make fit in a stock in tank sending unit. I'm not sure how your gonna fit an 044 in there unless your running an external set up.

 

[hendrixgr]

Hi.
Of course you are right, i am going with an all external system and yes the AEM was difficult to install in the first place.
I always had second thoughts about fitting the AEM pump but now i decided to make things right by fitting an external Bosch 044.
Not to mention that the AEM pump was drawing too much current bringing my charging system to his knees (13.2v @ 5000 rpm) and my tuner also told me that he didn't liked it from the start as it was fluctuating a bit.
The funny thing is that it was the most silent pump i have used by far including the oem one.
I will get the AEM pump Monday night at my hands so i can examine it thoroughly in order to find out if i got a faulty unit
or the installation wasn't good enough or something else was the cause (like bad fuel).
Chris

 

[dadofthree]

It might be a filter issue. Have you checked or changed your fuel filter ?

 

[hendrixgr]

Re: aem fuel pump emmits a high pitched sound

It might be a filter issue. Have you checked or changed your fuel filter ?

No but i will do it today as i remove the pump.
You might be right and it is a clogged filter but the tank was cleaned and pump installed just a couple months ago...
Of course there is always the possibility that i got dirty fuel the last time i filled her up.
The pump was very silent during priming (it was actually priming ok) and it would only start whining (a high pitched whistle like sound) minute or so after the engine was running at idle and i am almost certain that the whining sound was going away at higher throttle settings.
Another thing i noticed from the day i installed the AEM pump was the strong smell of fuel coming from the tank when parking with the engine off and no there was not a leak anywhere, i checked.
Maybe someone has encountered those symptoms before and can help us find out what is the culprit.
Anyway today i shall probably find out....
Chris

 

[dadofthree]

I was thinking bad fuel. Mine started whining when the filter became clogged. You wouldn't believe the crap I poured out of mytank when iI replaced my pump.

 

[hendrixgr]

I was thinking bad fuel. Mine started whining when the filter became clogged. You wouldn't believe the crap I poured out of mytank when iI replaced my pump.

Let's hope that this is the problem although installing a Bosch 044 is something that i always wanted to do.
Chris

 

[mjl3truck]

You could put a Bosch 69420 in the tank. It draws less amps than the AEM and if you buy it through Rock Auto the price is pretty good. If you are N/A should be plenty of pump.
fuel pump??
http://www.saarelat.org/Fuel-pump/index.html
Gen2 fuelpump upgrade - tested and done

 

[hendrixgr]

Ok here are some photos.
The problem was bad fuel that clogged the filter and damaged the pump.
I installed a Bosch 044 and to be honest it works so much better, the engine idles better and smoother and accelerates visibly better.
Not to mention that it draws a bit less current.
The AEM pump was making the engine run rough from idle to 4500 rpm from day one, maybe i got a defective one.

If you are N/A should be plenty of pump.

Unfortunately my bike is turbo and i need at least 160 l/h at 5 bar.
Chris

 

[E Zurcher]

I think there are a lot of people who have never changed their filter who have no idea what they are missing. Our bikes deliver so much power and the loss can be so gradual that it's hard to tell until you change it out then holy cow! Same goes for cleaning injectors. I know they are very expensive for what they are but they are a filter and do get clogged. If you disassemble one you will be amazed at how small the filter element actually is.

Symptoms of clogged filter include

High pitched whining, extended prime time, stumbling or falling on its face under hard acceleration, increase in acceleration when you back off the throttle slightly.

A good pump and filter makes a kind of whooshing sound when it primes, hard to describe but when it clogs you can hear the difference.

It doesn't surprise me that this is not mentioned in the manual because it is a high cost item to replace but maybe every 25000 miles is a good starting point.

 

[hendrixgr]

Everything you said is correct but this filter is two months old!!!
There was definitely something bad in the fuel that caused all those problems.
Anyway the bike works so much better now, the bosch 044 is a better pump (i don't know why but the engine is stronger and smoother) and the fact that i can easily replace the filter now makes me sleep better.
Chris