Nismo Fuel Pump Whining Noise??

[N/A®]

I have a Nismo Pump in the skyline. My question is why is it sometimes it constantly whines... (normal pump noise) whilst the car is running. Which should be what its suppose to be doing.

However sometimes it makes no noise at all. Is it on the way out?

Thanks

[Horus]

I knew someone who had the same fuel pump, and it whined like a mofo as well, you could hear the damn thing from 20 meters away, hence Im pretty sure that its normal for those fuel pumps to sound like that

[Revhead]

I think the question was, why is it sometimes quiet?

I don't know, but I'd be wondering if it wasn't loose on the bracket. Sometimes it sits nicely so it doesn't move, sometimes (hit a bump or something) it'll vibrate against something and obviously you'll hear the noise. If it's not that, then without more info (or someone who knows of common problems with these pumps) you might have trouble getting answers.

[tridentt150v]

Fuel pumps maintain a pressure head in the fuel system, it whines when it is working, it stops working when the pressure head level is reached, and then kicks in and starts pumping again when the pressure drops below ..... [a set level]. It will always be working when you are booting hard, speeding, racing etc, it will be intermittant when you are cruising, driving through traffic, or in car parks etc. A fuel pump [a good one] is --in theory--designed to give a constant pressure/flow of fuel at the vehicles maximum potential, when you are not using the vehicles maximum performance potential the pump does the job so easily it can have a rest [sort of]. Most fuel pumps fitted are actully overdesigned, so that you can fit your fmic, exhaust, biggish turbo etc and still retain the std fuel pump. You will eventually max them out when mods outstrip the fuel pumps ability to provide.

[Revhead]

I thought fuel pumps always worked at the same speed, and the fuel pressure regulator returned excess fuel from the rail to the tank via the return line???

[N/A®]

Mine whines even at idle.. especially if the car is full of fuel. But at times, there is no noise at all. Any help?

[mabru]

There is a gadget called the fuel pump control modulator FPCM which is basically a switching unit. You can bypass it by grounding the fuel pump straight to the inside of the boot. There have been many threads on this, the FPCM is the culprit sometimes when you're coasting and pop the clutch and the car stalls out for no reason at all. Sometimes it's not fast enough to catch up when you drop into neutral.

[Pawley]

we should hook up Ken, and compare whines. I thought my pump was standard, but it does whine like a mofo after a spirited run or in the heat.

[3R1K]

Using same fuel pump, it makes noise after you start and it will go away after 30 or 40 secs.

You can also hear the noise if you put your foot on pedals to let you know that fuel is pumping.

That's what happen in my car