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 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.

[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.

[dayj1]

Originally Posted by LS-K

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

The Walbro 255 only pulls about 10 amps. The 16 gauge wire that comes on the sender will work fine for that since it is less than a foot long. The problem is with the connector (instead of the wire gauge).

Unless you have the correct new terminals to crimp on larger wire, I think you'll be better off soldering the female terminals on the existing wires to the male terminals on the bulkhead. My logic on that one is that solder is for an electrical connection not for a mechanical connection. You want the terminals to provide the mechanical connection and the solder to provide the electrical connection. By soldering, you'll keep the resistance low and prevent the resistance (and heat) that melted the first connector.

[LS-K]

Originally Posted by dayj1

The Walbro 255 only pulls about 10 amps. The 16 gauge wire that comes on the sender will work fine for that since it is less than a foot long. The problem is with the connector (instead of the wire gauge).

Unless you have the correct new terminals to crimp on larger wire, I think you'll be better off soldering the female terminals on the existing wires to the male terminals on the bulkhead. My logic on that one is that solder is for an electrical connection not for a mechanical connection. You want the terminals to provide the mechanical connection and the solder to provide the electrical connection. By soldering, you'll keep the resistance low and prevent the resistance (and heat) that melted the first connector.

Got'cha!! So pretty much anything that has a plug should be de-pinned from the plug and soldered to its male counterpart?

[dayj1]

Originally Posted by LS-K

Got'cha!! So pretty much anything that has a plug should be de-pinned from the plug and soldered to its male counterpart?

Yeah, that's what meant about the bulkhead connector just because it's so cheaply made. The connector that actually plugs into the fuel pump is much better quality. I've never soldered that one.

[LS-K]

Originally Posted by dayj1

Yeah, that's what meant about the bulkhead connector just because it's so cheaply made. The connector that actually plugs into the fuel pump is much better quality. I've never soldered that one.

cool, I'll only de-pin and solder the grey connector that goes from inside of the sender to the inside part of the bulkhead. Thanks once again.

Hey when I pulled the tank and pump this past weekend, I tested the pump directly off the battery to make sure it still worked. I did this a couple of times and it just sucked air through it, any chance I might have messed it up or will I mess it up if I continue to test it like that?

[dayj1]

Originally Posted by LS-K

cool, I'll only de-pin and solder the grey connector that goes from inside of the sender to the inside part of the bulkhead. Thanks once again.

Hey when I pulled the tank and pump this past weekend, I tested the pump directly off the battery to make sure it still worked. I did this a couple of times and it just sucked air through it, any chance I might have messed it up or will I mess it up if I continue to test it like that?

The fuel cools the windings in the pump, so you shouldn't run it very long in open air. But I don't see how a quick connection just to see if it runs would hurt anything. As long as you're only talking about a couple of seconds, I'd say it's fine.

[LS-K]

Originally Posted by dayj1

The fuel cools the windings in the pump, so you shouldn't run it very long in open air. But I don't see how a quick connection just to see if it runs would hurt anything. As long as you're only talking about a couple of seconds, I'd say it's fine.

Cool, thanks again. I was kinda scared for a bit.

[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.

[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 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".

[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.....