Walbro pump failure

[LS-K]

Anyone ever experience a brand spankin' new Walbro pump just die out of no where?

I drove the truck from the muffler shop last Thursday just fine without a hitch and just yesterday I noticed my pump wasn't "priming" when I would turn the ignition switch forward.

Since last Thursday, I have only turned the truck on and ran the engine three times and it idled just fine. Just for info, the PCM was tuned with deleted VATS.

I went ahead and jumped the pump directly to the battery and still nothing, no priming, no pumping, no nothing. I'd like to see if anyone has seen this before I drop the tank this weekend.

thanks in advance

[BR3W CITY]

Is this a 255?

I've used a few of them, both from Walboro and from the 8 other companies they get sold under. The only time I've had one go bad was due to it going dry a few times (aka user error), and this was always on externally mounted pumps...its harder to get them to pump dry in-tank.

Are you hotwired or running off the PCM control? What kind/size of filter are you running (and where)?

After only 3 uses, its either a fluke, or something was done to fry it. Even the "worst" generic fuel pumps last longer than that.

[LS-K]

Originally Posted by BR3W CITY

Is this a 255?

I've used a few of them, both from Walboro and from the 8 other co. anies they get sold under. The only time I've had one go bad was due to it going dry a few times (aka user error), and this was always on externally mounted pumps...its harder to get them to pump dry in-tank.

Are you hotwired or running off the PCM control? What kind/size of filter are you running (and where)?

After only 3 uses, its either a fluke, or something was done to fry it. Even the "worst" generic fuel pumps last longer than that.

Yea 255.

Its off the PCM and Its an in-tank pump. I ran the classic 87 fuel tank in tank pump and the corvette filter

[BR3W CITY]

So if you jump straight off 12v, the pump does NOTHING? NO sounds at all?

You may have to actually pull the pump itself, to check for;
a) debris impeding the suction (or clogged sock filter)
b) that the wiring to the pump motor itself is correct and in place
c) try jumping straight off 12v again and see if there is any sound/motion/vibration from the pump.

When it stopped working, were any fuses blown or any codes thrown?

[LS-K]

Originally Posted by BR3W CITY

So if you jump straight off 12v, the pump does NOTHING? NO sounds at all?

You may have to actually pull the pump itself, to chis cck for;
a) debris impeding the suction (or clogged sock filter)
b) that the wiring to the pump motor itself is correct and i. place
c) try jumping straight off 12v again and see if there is any sound/motion/vibration from the pump.

When it stopped working, were any fuses blown or any codes thrown?

Correct. No sounds or anything. I'm dropping the tank this weekend to have a look. I have not ran a scanner through it for codes. I wanna say the wiring is correct since its always primed right and I've never had issues with it even when I would do 30 second starts during the swap

[LS-K]

Well got to tear down the truck this weekend and removed the tank...I guess it wasn't the pump after all. The sender was purchased from classic parts, and the pump and everything else attached to my engine harness is fused/relay'd through a current performance standalone fuse/relay block.

[BR3W CITY]

Dang so it melted the molex plug?

Nothing like having a hot +12v source ready to spark, right above the fuel source.

[LS-K]

Originally Posted by BR3W CITY

Dang so it melted the molex plug?

Nothing like having a hot +12v source ready to spark, right above the fuel source.

Yup! I remember re-wiring the fuel pump relay portion of the current performance fuse/relay box since it wouldn't "prime" the pump during the early stages of my build.

[BR3W CITY]

So this was a result of the rewire? I'm just curious what you think the total failure was; are you thinking the wiring itself was a problem, or did the pump pull to many amps and CAUSE a failure?

I'd still suggest testing the pump while out with a generic 12v source and an multimeter on it. See what the motor is pulling for amps, and if its very high, we can assume that its what caused the failure.

Its also a nice idea to use some heavier gauge wiring when doing a hotwire/hardwired fuel pump (or air pump, oil pump etc).

[dayj1]

My money says it was the result of a cheap connector. That particular style of connector isn't the best in the world. It was questionable on the OEM GM senders. The Asian repopped versions floating around in the aftermarket are even worse. On the last couple of swaps that I've done, I removed the plastic housing from the plug and soldered the connectors directly to the bulkhead plug in the sender. That's because I had exactly the same thing happen.

[LS-K]

Originally Posted by dayj1

My money says it was the result of a cheap connector. That particular style of connector isn't the best in the world. It was questionable on the OEM GM senders. The Asian repopped versions floating around in the aftermarket are even worse. On the last couple of swaps that I've done, I removed the plastic housing from the plug and soldered the connectors directly to the bulkhead plug in the sender. That's because I had exactly the same thing happen.

You mind sharing pics and what not on how to do this? I wouldn't want this happening again, much less anywhere near fuel.

[dayj1]

This isn't my post, but it shows what I'm talking about (in the second picture).

http://www.impalassforum.com/vBullet...46&postcount=2

[LS-K]

Originally Posted by dayj1

This isn't my post, but it shows what I'm talking about (in the second picture).

http://www.impalassforum.com/vBullet...46&postcount=2

Thanks, I'll do exactly this when I get my new sender this week. I'll probably re-wire with thicker gauge wire too.

[ls1nova71]

Originally Posted by dayj1

My money says it was the result of a cheap connector. That particular style of connector isn't the best in the world. It was questionable on the OEM GM senders. The Asian repopped versions floating around in the aftermarket are even worse. On the last couple of swaps that I've done, I removed the plastic housing from the plug and soldered the connectors directly to the bulkhead plug in the sender. That's because I had exactly the same thing happen.

X2. I can just about guarantee this is your problem. I have replaced more Chinese fuel senders because of this type of bad connection than I can remember. My work just insists on buying Dorman senders, and they just don't last. I have replaced some because the fuel gauge quits working, and you pull the sender out and there will be almost no insulation on the wires, it's like it just shrinks up and leaves bare wires to touch other parts of the sender.

[LS-K]

Originally Posted by ls1nova71

X2. I can just about guarantee this is your problem. I have replaced more Chinese fuel senders because of this type of bad connection than I can remember. My work just insists on buying Dorman senders, and they just don't last. I have replaced some because the fuel gauge quits working, and you pull the sender out and there will be almost no insulation on the wires, it's like it just shrinks up and leaves bare wires to touch other parts of the sender.

Just to clarify, you recommend Dorman senders right?

[ls1nova71]

Originally Posted by LS-K

Just to clarify, you recommend Dorman senders right?

Only if your idea of a good time is dropping a tank to replace one when it craps out.....

[LS-K]

Originally Posted by BR3W CITY

So this was a result of the rewire? I'm just curious what you think the total failure was; are you thinking the wiring itself was a problem, or did the pump pull to many amps and CAUSE a failure?

I'd still suggest testing the pump while out with a generic 12v source and an multimeter on it. See what the motor is pulling for amps, and if its very high, we can assume that its what caused the failure.

Its also a nice idea to use some heavier gauge wiring when doing a hotwire/hardwired fuel pump (or air pump, oil pump etc).

To be honest, I don't have the slightest clue on what caused it. I just mentioned the rewiring part so you guys could get the whole story or what I've done to this part or my build. I'll do the test with the multi meter, but do I just run the pump out in the air or in some tank with fuel? don't want to burn the pump by running it out in the air and sucking up air,<<< that's just my thought.

[BR3W CITY]

It might still be a good idea to drop it in a bucket of fuel or water and test the pump under the load from the liquid. The fluid dynamics of fuel/water mean its harder to pump than air, so the pump will "work" harder to do it.

If you start to see 15+ amps being drawn for any sustainable time, then you have a problem greater than just the wiring.

[LS-K]

Originally Posted by BR3W CITY

It might still be a good idea to drop it in a bucket of fuel or water and test the pump under the load from the liquid. The fluid dynamics of fuel/water mean its harder to pump than air, so the pump will "work" harder to do it.

If you start to see 15+ amps being drawn for any sustainable time, then you have a problem greater than just the wiring.

Yea I'm definitely testing the amps its drawing for sure. I think I will dump it in water or fuel just so I don't spend more money later in case I burn the pump doing "air tests".

[Hart_Rod]

What EFI wiring harness are you using? Where does it receive power from? Interior fuse block or directly from the battery?

[LS-K]

Originally Posted by Hart_Rod

What EFI wiring harness are you using? Where does it receive power from? Interior fuse block or directly from the battery?

I'm using the original harness that came with the engine. I added a current performance relay/fuse block.

[Hart_Rod]

Originally Posted by LS-K

I'm using the original harness that came with the engine. I added a current performance relay/fuse block.

I would wire the pump like this:

[LS-K]

Originally Posted by Hart_Rod

I would wire the pump like this:

I'll double check my relay/fuse block wiring for my fuel pump before reinstalling the tank this weekend? I'll double check everything you and the rest of the guys here suggested. Very reasonable and logical ideas. Thanks!!!

[LS-K]

Originally Posted by Hart_Rod

I would wire the pump like this:

Take a look Hart_Rod....

This is what I had in my Current Performance fuse/relay block. I'm sure I am the culprit, I remember switching some wires up in here because the pump wasnt "prime'ing" for those two seconds.

[solidaxel]

I like your camera!
That is a very good clear picture!