Fuel Pump, vapor-lock, or ???

'97 GMC K1500, 5.7L
I was towing my trailer at 65-70 when all of the sudden it just died.
No lites on dash, just quit, like running out of gas. Gas was 3/4 full, that wasn't it. would not start. I checked for spark, good. That leaves fuel. I checked for the typical 'buzz' of the fuel pump. It did make a couple of strange squeeks, but continued buzzing about normal. still no start. I tapped on the pressure check valve on the fuel rail twice, got a little spray of gas and air, (I have never done this, so I'm not sure what's normal, but it did have fuel). Tried it again, and it started! Now I was worried the whole way home it was gonna die again, NEVER DID! WTF?

This is the hardest I've ever worked this truck so that's a factor. I've towed the trailer (avg. 5000 lbs.) several times, but always localy, This was a long trip to southern Utah (350 mi. and warmer!) for some Dirtbike riding! We made it ALL the way down, and half way back before this happened. It was on the freeway, and even on a flat, thank god! But there I was, family and all, side of the road, in the middle of nowhere! :shakehead

Once it started (about 30 min later) it ran fine, even after stopping for gas again and shuttin it down. And still runnin at this writing. So, whatcha think? Fuel pump glitch? (replaced about 5yrs ago) Vapor-lock? (Does that even happen on these high pressure fuel lines?) Or something else?

Thanks,
Don't wanna be stuck in "The Hills"

'97 GMC K1500, 5.7L
I was towing my trailer at 65-70 when all of the sudden it just died.
No lites on dash, just quit, like running out of gas. Gas was 3/4 full, that wasn't it. would not start. I checked for spark, good. That leaves fuel. I checked for the typical 'buzz' of the fuel pump. It did make a couple of strange squeeks, but continued buzzing about normal. still no start. I tapped on the pressure check valve on the fuel rail twice, got a little spray of gas and air, (I have never done this, so I'm not sure what's normal, but it did have fuel). Tried it again, and it started! Now I was worried the whole way home it was gonna die again, NEVER DID! WTF?

This is the hardest I've ever worked this truck so that's a factor. I've towed the trailer (avg. 5000 lbs.) several times, but always localy, This was a long trip to southern Utah (350 mi. and warmer!) for some Dirtbike riding! We made it ALL the way down, and half way back before this happened. It was on the freeway, and even on a flat, thank god! But there I was, family and all, side of the road, in the middle of nowhere! :shakehead

Once it started (about 30 min later) it ran fine, even after stopping for gas again and shuttin it down. And still runnin at this writing. So, whatcha think? Fuel pump glitch? (replaced about 5yrs ago) Vapor-lock? (Does that even happen on these high pressure fuel lines?) Or something else?

Thanks,
Don't wanna be stuck in "The Hills"

check the ground connections at the frame rail next to the fuel tank,,,,could also be the fuel pump relay...

I would replace the relay any time the fuel pump is replaced...the defective fuel pump could cause the contacts to get damaged ....Also this is a 1997 vehicle since its over 10years old these electrical parts are worn....

That's the way my 97 did when the pump died first two times.
I've been carrying a pressure gauge ever since.
Also learned about the pigtail near the fuses under the hood that will activate the pump when connected to 12volts.
All this fuel pump stuff brings back memories of the 48 ford flathead that I owned as a kid.
Most owners told me to carry a spare fuel pump and wrenches.
At least the pump was on top of the engine.
Bob B

I belive I know where the relay is, I'll look into that.
Bob, This pigtail you speak of, can you give me some more info on that? I'd like to see if I have that also. And the gauge you use, Do you check the pressure at the 'shraeder valve' on the fuel rail just above the intake manifold? or somewhere else?

Thanks

I belive I know where the relay is, I'll look into that.
Bob, This pigtail you speak of, can you give me some more info on that? I'd like to see if I have that also. And the gauge you use, Do you check the pressure at the 'shraeder valve' on the fuel rail just above the intake manifold? or somewhere else?

Thanks
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Hi,
I think most cars or trucks have the jumper, Mine is a 97 K1500. My wife's car is a 91 Cad STS and in a different location it has one.
The pigtail is just behind the fuse/relay box where the fuel pump relay is.
It looks like a 3 inch wire not plugged in. The big screws on the rear of the relay box are 12 volts so it only needs a short jumper to activate it.
I did have to replace the relay once also.
Yes check pressure at the schrader valve.
BTW, THe comment to chech the ground connection at the tank is a very valid one, a wire from the connector goes to the frame and is the return for the pump.
Also the connector itself can corrode the individual connectors. there was a notice about replacing some of the connectors with a different type. A friends Blazer was working intermittently so he had the pump replaced. Then it failed in the middle of nowhere Nevada , so it was replaced again, then it failed in the desert camp, We dropped the tank out there and I inspected the connector where we found a very burned pin. Obviously neither mechanic ever checked it. We borrowed a connection from the underhood light to fix it.
After our return home I was at the Napa store and I noticed a large picture poster on the wall showing the exact failure (burned pin) and warning to check this area before replacing the pump.
Bob B