slashdawg00110

I can hear the pump change volume and pitch when the engine speed increases. Normal? Indication of problems with pump? Sign of fluctuating voltage?

Pump is mounted on frame rail, wired to fuse box through relay. Switched on/off via stock ignition switch wiring. Holley FPR. Return line capped in engine bay. Nikki carb.

mazdaspeedrex

Normally there should be no change in the noise. Has it done it since it was installed? It may need to be wired through a different fuse. I have a Holley blue on mine and the pitch is always the same. I wired mine right to the stock fuel pump wiring and it worked fine.

trochoid

iTrader: (6)

Most have thier exhaust so loud they never hear the fluctuations in a non-return system. The return ones fluctuate too, not as much though. The volume fluctuations is tied to the internal pressure bypass releasing.

mikewoodkozar

Yeah, i have a carter non returning pump and can hear the fluctuations at times, but the respeed fuel pressure gauge stays constant

slashdawg00110

Thanks for the replies. I think it's probably normal. Not a huge change in sound when engine speed goes up. Otherwise pretty much constant tone and volume.

I haven't used this pump for a while but had to install it after a Mallory pump crapped out. The Mallory was much quieter (georotor versus vane-style?).

trochoid

iTrader: (6)

Yeah, the gerotors are much quieter, they also last longer in bypass system.

Vashner

Could be the alternator acting up and or battery connections.

I was saying in another post when I installed a sub amp the headlights would dim to the beat.

slashdawg00110

I need to check out the electrical system. I noticed that the headlights get a bit brighter when I increase engine speed from idle.

Vashner

It's just that the stock alt is too low (amps) for modern electronics. On that fuel pump do you have the right fuse amps?

jay85gs

If you want to hear less noise mount your pump with some rubber mounts, my carter pump came with these and made a huge difference.

sgieldon

I used to hear my aftermarket Fuel Pumps change sound.
Like when you would use the turn signals or pump up the volume.

Straight from Painless Performance!
A relay will prevent voltage drops at the pump thus maintaining constant fuel pump pressure, and will prevent fuel pump amperage overloads from damaging the electrical system.
I'ts a good idea to relay your fuel pump for the street and a must when your are racing.
This unit will solve the power draws you are hearing now cause it's a dedicated setup.
Check it out @ www.painlessperformance.com

I have bought some other wire goodies from them in the past years and have had no problems with any of them.

I bought these Painless Wire Fuel Pump Relays from Summit Racing and have used this w/ Mallory-Carter & Holley fuel pumps.
5- 1st Gens over the years.
No more fluctuation. Part #50102 $28.95US
You wire it directly to the battery.
sgieldon
steve

mazda6guy

iTrader: (1)

Yes I was just reading this in the most recent Summit catalog. This relay system from painless is my next purchase. Just installed my Holley fuel pump and FPR yesterday on a Nikki setup. Made a big difference for me. My old pump was really weak and plus the ground wire was severely frayed on the pump itself.

jay

I used the Painless Relay kit from Summit for my Holley Blue, its a good kit. Just hooked one of the wires to the stock pump wiring and ran one of the lines from the battery back to the floor near the stock pump area. Throw in a toggle switch and you got anti-theft device. My Holly Blue was loud too, even with rubber backing, it varied in noise every now and then also. Then it burned up. You might want to run larger line to carb. 3/8" is what they recommend. Hope you have a longer lasting pump then mine.