2007 Tahoe 5.3L FF 2WD Extended Crank Before Start w/No Fuel Pressure w/Key in Start Position

Bigjayallday

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What could be my issue? I have a 2007 Tahoe 5.3L FF 2WD with an Extended crank that goes on for at least 6 sec and then I’ll shut it off and it’ll turn on the next try. What’s crazy is that the truck runs fine after and maintains a consistent fuel pressure between 52-55psi. However when I put key in start position I was receiving 0 psi. I switched the fuel pump relay out and then my fuel pump stood on constantly even after removing the key while truck was off. So for about 2 weeks I had to remove the fuel pump relay after turning it off so it wouldn’t drain the battery. I read in another post this sometimes happens with new relays but while it was doing that my truck had no problem turning on and seem fixed. However, the starter began acting normal and the fuel pump would shut off w/the engine like normal and the extended crank came back! Now to try and remedy the situation I’ve tested the fuel injection connectors with Noids which was fine and that means the signal from the computer is coming thru the connectors. I removed the fuel rail to individually clean each injector and they all sprayed fine and came back at 12.3 ohms when tested w/multimeter. I’ve changed out the oil and filter, new Acdelco spark plugs and wire harnesses, new Evap, and new MAF sensor. I tested the new fuel relay and its working fine. I stuck a tpin in the fuse box where the fuel relay would normally be to test the signal from the pcm and cranked the engine while putting a probe light on the tpin and everything lit up showing the signals good. I jumped the fuel pump from the relay and it turns on. However, it still gives me a long crank before having to turn it off and then it’ll start the 2nd time. So I am thinking of cutting into the wire cover that covers the wires coming from the main fuse box to the fuel pump so I can test the signal from those wires. Can it be the oil pressure switch? I’m so puzzled. Someone help with an answer. Because based off what i mentioned the fuel pump should be fine then, right? So what else could it be???
 

wjburken

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Does this happen every time, or just after the vehicle sits for an hour or so?

How many miles on the vehicle?

I would not necessarily rule out your fuel pump being bad.

My 2007 Yukon started doing the same thing after it sat for a while and it ended up being the fuel pump. Once that was swapped out, problem went away. It was bleeding off pressure while it sat and the first start attempt would almost get it back up to pressure then time out. The 2nd attempt would get it going.
 
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Bigjayallday

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Does this happen every time, or just after the vehicle sits for an hour or so?

How many miles on the vehicle?

I would not necessarily rule out your fuel pump being bad.

My 2007 Yukon started doing the same thing after it sat for a while and it ended up being the fuel pump. Once that was swapped out, problem went away. It was bleeding off pressure while it sat and the first start attempt would almost get it back up to pressure then time out. The 2nd attempt would get it going.
This happens every time it’s turned off. The Tahoe has 214k miles. Thanks for your reply. That’s what I initially thought but I was trying to rule out everything else first but that just may be the issue. So when your truck did start up did it run fine or did it ever die out or lose power on you.
 

wjburken

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This happens every time it’s turned off. The Tahoe has 214k miles. Thanks for your reply. That’s what I initially thought but I was trying to rule out everything else first but that just may be the issue. So when your truck did start up did it run fine or did it ever die out or lose power on you.
My Yukon ran just fine once it started. Never had a hiccup or loss of power.

The pump itself was fine, and could keep up. The check valve, or whatever is used to hold pressure, failed and let pressure bleed off while sitting.

214K is about where mine started to give up the ghost as well. With a friend helping, it’s not too bad of a job to swap fuel pumps. Try and run the tank down as far as you can before dropping it.
 

iamdub

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+1 to replacing the fuel pump.

Classic check valve failure. The fuel system is losing its prime. Usually, it's a slow bleed and is only an issue after sitting for a while, like over night. Yours is draining back fast. You just happened to get a stuck relay during your diagnostics, which introduced another problem but fixed the long crank problem since it was powering on the fuel pump right away. The time it took to do that, reinstall the cover, close the hood, get in, etc. was plenty of time to prime the fuel system. Next time you go to start it after sitting for a while, turn the key on, not crank, and wait a few seconds and turn it off. Repeat this once or twice. Then turn the key to start it as normal. It should fire up right away.

The valve is built into the pump. At that mileage, replace the whole assembly.
 
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Bigjayallday

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My Yukon ran just fine once it started. Never had a hiccup or loss of power.

The pump itself was fine, and could keep up. The check valve, or whatever is used to hold pressure, failed and let pressure bleed off while sitting.

214K is about where mine started to give up the ghost as well. With a friend helping, it’s not too bad of a job to swap fuel pumps. Try and run the tank down as far as you can before dropping it.
 
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