Electric whine noise mystery in rear of Voyager '94 6cyl. 3.0L

We have a Plymouth Voyager '94 6 cylinder 3.0L with fuel injection. It
has 104K miles on it, and has been well maintained.

It had a whine noise in the rear of the car that developed one long
trip. It would whine like a high rev electric motor when you just
turned the ignition switch one click (this did not start the engine).
The whine would persist as long as you drove the car.

From reading on these group pages this seemed to indicate the electric
fuel pump was bad. The pump is located in the gas tank . We took it to
a mechanic and he confirmed the diagnosis but he did not have time to
repair it till the weekend. So we jacked the car up in the rear and we
replaced it ourselves with a NAPA fuel pump part... It fit OK and no
leaks.
Then I started to replace the fuel filter.

When I looked at the fuel filter cannister under the right middle
undercarriage. It was shiny new. We looked at a previous repair bill
done by our local mechanic a couple months ago and they replaced this
fuel filter. So I did not bother with replacing it.

So we start the car up and it runs....BUT there is still a whining
noise coming from the rear...which I guess suggests the fuel pump is
under strain from something.

1. Any ideas what to look at next? Junk clogging the lines?

2. Is there a second fuel filter in the car?
Perhaps the fuel filter the mechanic put in was defective (or
backwards).

3.We would also appreciate some advice on discharging the injector
system pressure too.

Thanks,

Nate

 

Some pumps are noisy.

No. There are micro screens at the inlet side of the injectors,
but when they start to plug, you tend to experience other
driveability symptoms.

It probably has an arrow on it indicating direction of fuel flow,
otherwise, the crimped end usually faces the engine.

Disconnect fuel pump harness, start engine until fuel pressure is
depleted.
Connect two jumper wires to a fuel injector, connect them to the
battery for a few seconds.
Install fuel pressure gauge to fuel rail Schraeder valve (if
equipped), bleed fuel pressure out of gauge purge valve into
safe/suitable container.

 

I had a weird thing like that too. My fuel pump started whining, at
least that's what the mechanic said. During the couple of days that I
was thinking about fixing it, it stopped and hasn't reappeared in six
months. I've had a lot of "weird" things happen with this van (94
T&C)

Lisa

 

I'm not sure whining is bad, but obviously we're not hearing the sound - you
are. I would suggest doing nothing. In fact, I would have suggested that
before you changed it. When the whining stops, that's when you're in trouble
(haaaa ha ha).

I can hear the fuel pumps on all my cars. They all whine, naturally, because
they're all rotary machines operating at high rpm. If one of them got really
loud, then I guess I would worry, but that's never happened to me. I always
diagnose them on pressure rather than sound.