2007 gmc sierra ltz 5.3 died while driving

Doug_Scott · October 5, 2014

From what I can find, your gas tank holds somewhere between 26 and 27 US gallons. At a quarter tank, that will be about 6.5 gallons left. Each gallon weighs approx. 6.5 pounds, so you have about 43 pounds of fuel in the tank. It is not overwhelmingly heavy, but, trying to hold a tank with 40 pounds of fuel moving around in it can be a bit daunting if you are on your own. Tank is also plastic, and I am not sure how it behaves if it happens to drop from a couple feet with 40 pounds of fuel in it.

If you drop the tank, have someone help. And once the tank is out, have enough gas cans around to hold the fuel in the tank, and dump as much of the fuel out before trying to put it back in. Make sure you hose the top of the tank off before pulling the sending unit and pump. You may want to empty the tank into a big bucket, and then either fill tank back up after installing from that bucket. If you do, make sure bucket is clean, and when transferring it back into the tank, put an old t-shirt over the funnel to filter out any crap you missing when cleaning the tank off. Don't cut the skirt, run the fuel through a double layer of t-shirt. BTW, do not toss it into the washing machine while it is wet, and do not just leave it all bunched up on the floor of the garage. If you want to keep the shirt, hang it up outside to dry, then hose it off a few times, let it dry again, hose it off again, and if the smell of the fuel is still strong, let it air some more. If you just toss it into the washing machine it can damage the internals, and will for sure transfer that gas smell into everything you wash for the next couple of months. I would just let it dry outside, and leave it there till next garbage day, and at that time, throw it out.

TJMaine · October 5, 2014

I would have checked the fuel pump control module. Bud who works for gm dealer says they like to go out at 100k or so. Gives symptoms of bad pump but the module controls the pump. Took mine out and had standing water in it. A lot easier to check that then the pump

gmc70 · October 5, 2014

I lifted the bed as much as possible, and checked power at the pump and I can hear the pump engage when the key is turned so could the pump be good?

Thanks for the t-shirt tip I'm sure my wife wouldn't appreciate the gas smell..

I would have checked the fuel pump control module. Bud who works for gm dealer says they like to go out at 100k or so. Gives symptoms of bad pump but the module controls the pump. Took mine out and had standing water in it. A lot easier to check that then the pump

I will check the fuel pump control module I might as well check everything.

Doug_Scott · October 5, 2014

I lifted the bed as much as possible, and checked power at the pump and I can hear the pump engage when the key is turned so could the pump be good?

Thanks for the t-shirt tip I'm sure my wife wouldn't appreciate the gas smell..

I will check the fuel pump control module I might as well check everything.

If the pump is running, and you are not getting any fuel out from it, then it is likely not pumping. Verify the fuel filter is not plugged as well if you have not already. You can disconnect the fuel line from the filter, point the line from the tank into a bucket or some receptacle to catch the gas, and turn the key on. Fuel should be coming out with some force behind it. This is a two person job, one will likely get dirty, the other won't. Do not leave the key on unless you have a large catch can. Not sure if they still do it or not, but, there used to be a spec for how much fuel is pumped in so many seconds. I would just check to see if it comes out under force for now.

gmc70 · October 6, 2014

Isn't the fuel filter I the tank on these trucks?

txab · October 6, 2014

Isn't the fuel filter I the tank on these trucks?

You have no external filter

Doug_Scott · October 6, 2014

It appears to be. Has to be one of the dumbest ideas ever. I could understand if external filters never plugged up, but we all know they do plug up.

Check for fuel flow as close to the tank as possible, if the pump is making noise, you are left with needing to verify fuel flow.

gmc70 · October 7, 2014

Well I ordered the new pump a Delphi, it should be here at the latest wed, I also tilted the bed up and I can only get it so far with that other bolt still in, any idea how much clearance would I need to replace that pump under the bed with it tilted?

Doug_Scott · October 7, 2014

Having never done it myself, I would expect you will need at least half to three quarters of the depth of the tank to get it out. At some point the sending unit will need to laid over on its side. At that point you are essentially out and should not need much more clearance. Make sure that the bed of the truck is not hitting any body panel and damaging it.

TJMaine · October 8, 2014

Not to be rude, but i am still baffled you havent checked all the cheaper and easier things first or posted any codes or anything..... I was ready to do the same thing you were, then I took that damn Fuel Pump control module out and it was pissing water out of it... replaced and problem solved.... ( after trip to dealer for program )

gmc70 · October 9, 2014

Well since there is power to the pump I figured the control module was good. I checked everything else.

Now that I have the fuel pump, tonight I had to drop the tank because the damn fuel line wont come off the pump even with a tool I bought at Oreillys the connector wont budge, dropping the tank was a breeze no weight to it at all.

TJMaine · October 9, 2014

I could be wrong, but the pump could be getting power from another source and the control module tells the pump how much to send and at what PSI... just a thought.... As a sys admin I tend to eliminate all the silly things before i touch the big items... if replacing a network cable can/would have fixed it why replace the switch?

Doug_Scott · October 9, 2014

I could be wrong, but the pump could be getting power from another source and the control module tells the pump how much to send and at what PSI... just a thought.... As a sys admin I tend to eliminate all the silly things before i touch the big items... if replacing a network cable can/would have fixed it why replace the switch?

I think the logic he is using is that if there is sufficient fuel in the tank, and if the pump is getting power, and he can hear the pump running, but there is no fuel coming out of it, then there is something wrong between inlet and the outlet of the pump. To me, that appears to be sound logic.

This may not be the actual pump itself, it may be the pickup filter on the pump, it may be the fuel filter built into the pump, it may be a crack in the inlet tube of the pump that is allowing air into the pump, it may even be enough crap in the bottom of the tank that it is blocking the inlet of the pump. All of these possibilities require removal of the pump to check.

gmc70 · October 10, 2014

The tank was empty that was the problem, the gauge said it had a little over a quarter tank left so the sending unit was bad, I bought a Delphi FG0909 pump but it wont seat in the tank it is about 1/4 inch to tall, the pump has these removable rubber feet on the bottom they are about 1/8 inch thick I wonder if I need those.

I also have the tank up on blocks but the pump wont seat all the way.

any ideas?