2007 gmc sierra ltz 5.3 died while driving

[gmc70]

hey guys, great site

 

I was driving home tonight with my sons 14-6 & 8 weeks, when all of the sudden I noticed my gas pedal went soft I looked down and there's no rpms so I throw in in neutral and try to start it but it wont start so I pull over and put it in park and try again, but it wont start it just turns over, I sat there and tried a few more times but no luck, so I pop the hood and check everything over and don't see anything out of place so I let it sit for a few and try again but still just turns over, So I called my father in law and we towed it home, it has gas and oil it wasn't hot, I have no Idea what it could be, the truck is a 2007 GMC sierra slt with the 5.3 engine,

 

Any ideas what it could be? fuel pump?

[gmc70]

One thing I did notice was that when I turned the key it kind of stayed engaged when I let off of it like it was continuing to turn over even when I let off of the ignition. very strange.

[Colossus]

how many miles

[gmc70]

107,000

[Doug_Scott]

Not sure when GM started doing it, but, it is not unusual for the truck to keep cranking after letting off the key until the engine starts, provided you let off the key in less than a second or so. I can sometimes get my seatbelt on while truck is still cranking with me not touching the key. My last two Pontiacs did that as well.

 

As for your truck, check fuel pump. Easy enough to check, turn key on, and check for fuel pressure at the Schrader valve.

[gmc70]

Could it be the relay?

[gmc70]

Not sure when GM started doing it, but, it is not unusual for the truck to keep cranking after letting off the key until the engine starts, provided you let off the key in less than a second or so. I can sometimes get my seatbelt on while truck is still cranking with me not touching the key. My last two Pontiacs did that as well.

 

As for your truck, check fuel pump. Easy enough to check, turn key on, and check for fuel pressure at the Schrader valve.

Thanks man I will check that in the am.

[TJMaine]

Mine did this.... Was the fuel pump control module or whatever the heck you call it... up under the bed... 100$ part from GM and 100$ program from GM dealer ( your prices and issues may vary )

[gmc70]

Borrowed a tester from AZ and hooked it up turned the truck over and no pressure.

 

So its the fuel pump.

[Doug_Scott]

Borrowed a tester from AZ and hooked it up turned the truck over and no pressure.

 

So its the fuel pump.

 

Or the relay, or the fuse, or one of the safety relays, or broken wire, or.....

 

A pump may indeed fix it, but you are rolling the dice. Check for power at the pump first, and also check the ground at the pump. Remember that you likely cannot return the pump if it turns out to be a fuse.

[gmc70]

 

Or the relay, or the fuse, or one of the safety relays, or broken wire, or.....

 

A pump may indeed fix it, but you are rolling the dice. Check for power at the pump first, and also check the ground at the pump. Remember that you likely cannot return the pump if it turns out to be a fuse.

 

Checked the fuse its good, not sure how to test the relay and neither AZ or O,reillys had the relay I will have to go to GM, I will check the power at the pump tomorrow and the ground, Thanks for the tip.

[Colossus]

If you have to pull the tank, you might as well replace the entire module in there, don't just do the pump only.

[gmc70]

relay is good, trying to remove the bed now as I was told that was the best way to access the pump, I was able to loosen all the bolts but one on the passengers side closest to the cab, it just turns and makes a noise and wont come out, any ideas, or would it be easier to drop the tank?

[Doug_Scott]

Chances are the nut has broken free. You may want to try to cut the head off the bolt, and once the box is off, fix the broken nut. There is also a fair amount of flex in the mounts, and if only one is still on, you may be able to lift the box high enough to get the pump out.

How much gas is in the tank? Gas weighs somewhere between 6 and 6.75 pounds per gallon. Keep that in mind when trying to drop the tank.

[gmc70]

_{There is about a quarter tank in it, do you think it would it be easier to try to lift the bed or should I just drop the tank? The location of the bolt would make it very hard to grind it off I would have to use something small like a dremel, That would take awhile....}