Whining under acceleration: Fuel pump going bad?

[Research Rat]

So, I'm getting around to investigating some potential issues with my 94 Mazda b3000. (I have another thread going on a rough running motor) http://www.therangerstation.com/forums/showthread.php?t=121160

I've noticed that the motor doesn't seem to run as responsive as it used to. The truck runs around town, the truck runs at highway speed, but when you mash the accelerator it just doesn't respond as well. I was reading up on the fuel system in the Haynes Manual and it referenced that one of the potential causes of performance loss is a faulty fuel pump. Over the summer I had a stuck fuel pump (I had to bang on the tank when turning the ignition to unfreeze it.) Like I mentioned the truck runs, so the fuel pump is at least working somewhat....

I've noticed lately that with the radio off I can hear a pretty loud whine that moves in tandem with acceleration of the truck. At a stop sign-no whine. As soon as the accelerator is depressed-then a whine. The whine seems to grow in intensity as acceleration increases.

Is it normal for the fuel injection system to emit audible "whining" when under acceleration? Or is this symptomatic of a fuel pump and/or injector issue.

Thanks in advance.
-Scott

 

[locovaca]

If you suspect a fuel pump the first thing to do is check your fuel pressure. Your symptoms are not what I would classify as normal fuel delivery issues. The whine is more likely to come from the transmission or the diff if it only does it while accelerating. Anyway, a fuel pump that is going out will probably show issues with fuel pressure, and that's cheaper and easier than blindly putting a new pump in there.

 

[06RangerXLT]

start with a fuel filter.

if that doesnt fix it check your pressure. fuel pumps dont normally half work, they either spin or dont.


the whining is you torque converter. your hearing it because your mind is thinking something's wrong, and your paying attention to noises you before ignored. mine does the exact same thing.

 

[Research Rat]

Thanks!

I should of mentioned that my 94 is a manual transmission 2wd.

Good point that I could be misinterpreting other sounds, but this whine doesn't really sound normal. It sounds similar to a power steering pump groaning when turning the wheel when not moving.

start with a fuel filter.

if that doesnt fix it check your pressure. fuel pumps dont normally half work, they either spin or dont.


the whining is you torque converter. your hearing it because your mind is thinking something's wrong, and your paying attention to noises you before ignored. mine does the exact same thing.

 

[Dirmaid]

is the wine in any particular gear? i was freaking out about my transmission making a whine after a glitch filled weekend at the track. thought i had broken something. then i found out 1st gear (at least on my transmission) is a straight cut gear, which always whines. helical cut gears are quieter thus don't whine. I just had never noticed it before so i got worried

 

[Research Rat]

I drove it for a bit today. The whine is in all gears and only when the accelerator is pressed. The whine immediately cuts out when the clutch is pushed in.

is the wine in any particular gear? i was freaking out about my transmission making a whine after a glitch filled weekend at the track. thought i had broken something. then i found out 1st gear (at least on my transmission) is a straight cut gear, which always whines. helical cut gears are quieter thus don't whine. I just had never noticed it before so i got worried

 

[newnthused]

I drove it for a bit today. The whine is in all gears and only when the accelerator is pressed. The whine immediately cuts out when the clutch is pushed in.

Did you ever figure out what the issue was?

 

[rusty ol ranger]

Did you ever figure out what the issue was?

If youre having a similar issue start a new thread and folks will be along to help