2002 Yukon fuel pump toast? Fixed

[Kgitti]

Ok I need y’all’s best psychic insight here because the truck is no longer running and I’m guessing now.
So here is the sequence:
1) the truck was running fine for a few weeks but the gas gauge was wonky. At idle the fuel gage would jump around from empty to full. When it said empty the low fuel light would come on too.
2) I tried the Chevron Techron thing which seemed to help a bit. I was planning deeper surgery when time allowed like a new fuel pump.
3) This morning after running an errand it started acting like it was starved for fuel and died in a store parking lot. I had it towed. It is not low on gas, but won’t start.
4) while still running (roughly) I was getting these codes and the bank 2 one.
5) I’m guessing the fuel pump? Intake manifolds seem intact.
6) Your insights please?

 

[Marky Dissod]

Check fuel pump wiring as well as fuel pump. Replace fuel filter regardless.

 

[Kgitti]

Check fuel pump wiring as well as fuel pump. Replace fuel filter regardless.

Will do thanks.

 

[Fless]

Do you hear the fuel pump run when you turn the key on?

Before you do anything document the fuel pressure at the fuel rail. You should be able to "rent" a fuel pressure gauge at your local auto parts store. Key on, engine off (KOEO), see if there is pressure. Alternatively, KOEO, put a rag over the Schrader valve on the fuel rail and push the center of the valve with a small screwdriver. The rag is there to protect you from spraying fuel if there is pressure.

If no pressure there, reach under the truck and whack the fuel tank a few times with a rubber mallet or your fist -- it might shock the pump into working, at least temporarily.

 

[rockola1971]

Typically before a pump dies the engine does NOT start immediately on the first crank and usually requires a 2nd crank. This goes on for weeks, months and even many months before the pump finally dies and leaves you stranded. It is possible for a pump to just die without any warning and that is usually caused by someone always running the tank really low all the time or even empty to the point the engine dies. The pump requires gasoline to cover most if not all of its body in the sump that is in the tank. Gasoline is actually used to cool the fuel pump.
I would check for burnt/bad fuel pump relay and the wiring harness burnt at the top of the tank then check for 12v at the connector at the tank with key on and engine cranking. Be aware with just key on the 12v will only be there for about 5 secs then turn off. While the fuel level sensor is mounted on the fuel pump assembly there is nothing in common to the fuel pump and your fuel level other than they both use the same wiring harness coming out of the tank and from the tank up to the firewall so it is possible you have wiring harness damage of some sort causing both problems.

 

[Kgitti]

Do you hear the fuel pump run when you turn the key on?

Before you do anything document the fuel pressure at the fuel rail. You should be able to "rent" a fuel pressure gauge at your local auto parts store. Key on, engine off (KOEO), see if there is pressure. Alternatively, KOEO, put a rag over the Schrader valve on the fuel rail and push the center of the valve with a small screwdriver. The rag is there to protect you from spraying fuel if there is pressure.

If no pressure there, reach under the truck and whack the fuel tank a few times with a rubber mallet or your fist -- it might shock the pump into working, at least temporarily.

 

[Kgitti]

I’ll give this a try tomorrow

 

[Kgitti]

I have pressure at the rail. Seems weak. I’ll get a gauge this aft to actually measure it.

 

[Kgitti]

I changed fuel filter just in case.
No one rents or loans a fuel pressure gauge here- must be some insurance thing.
There is some pressure there with KOEO. I bought a cheap pressure gauge and it doesn’t move the needle. Fuel pressure too weak? ****** cheap gauge? There is pass thru with the pressure relief knob.

 

[Kgitti]

Typically before a pump dies the engine does NOT start immediately on the first crank and usually requires a 2nd crank. This goes on for weeks, months and even many months before the pump finally dies and leaves you stranded. It is possible for a pump to just die without any warning and that is usually caused by someone always running the tank really low all the time or even empty to the point the engine dies. The pump requires gasoline to cover most if not all of its body in the sump that is in the tank. Gasoline is actually used to cool the fuel pump.
I would check for burnt/bad fuel pump relay and the wiring harness burnt at the top of the tank then check for 12v at the connector at the tank with key on and engine cranking. Be aware with just key on the 12v will only be there for about 5 secs then turn off. While the fuel level sensor is mounted on the fuel pump assembly there is nothing in common to the fuel pump and your fuel level other than they both use the same wiring harness coming out of the tank and from the tank up to the firewall so it is possible you have wiring harness damage of some sort causing both problems.

Whatever died, died without warning. Unless you consider the wonky fuel gauge a warning. It had always started flawlessly till then. Because of the wonky fuel gauge, I had not been running the tank low. Pounding the tank doesn’t do anything.
Relays are fine. I will try to check connections at top of tank. Elec. not my strong point and since I have MS not easy for me to get in there.