Is it my fuel pump or my imagination?

[Searay45db]

The other day while driving with the wife, she was yelling at me because the low fuel light was on. NP I told her, there are 6 gallons in reserve. 30 seconds later....rolled to a stop. Got some gas, started right up, in fact right up, didn't even cycle the fuel pump. Drove home, 2 minutes away. Went to go to take it to the gas station and would not start again. Put some more gas in, started. Drove 2 minutes away, and counting the gas I put it, it only took 26 gallons. In other words I was not out of gas. So I got out the old fuel pressure gauge. This is where it gets confusing.

When I cycle the engine, I get 58 psi, but after 3 seconds, it drops to 49 psi. After 5 minutes it drops maybe a lb. So, is this normal and I have a problem somewhere else?

2005 GMC Yukon Denali XL 6.0 AWD

 

[ivin74]

How many miles are on your suv, if the pump has never been changed out I would try that first. I have a feeling thats what maybe your problem.

 

[Searay45db]

140k, however my others have over 200k on the original. Changing this out without being sure is a nasty job. Started fine today, ran a couple of errands with it...

 

[ivin74]

140k, however my others have over 200k on the original. Changing this out without being sure is a nasty job. Started fine today, ran a couple of errands with it...

My fuel pump went out at 130k and I used the autozone brand and went to shit in 12k miles, had to place it again but the 2nd time I used the oem pump no issues since. I did not drop the tank at all, remove the drivers rear bucket seat cut a hole on the floor board and pump was out in no time. Best mod ever, I cant believe GM did not install an access door for the pump.

 

[Searay45db]

My fuel pump went out at 130k and I used the autozone brand and went to shit in 12k miles, had to place it again but the 2nd time I used the oem pump no issues since. I did not drop the tank at all, remove the drivers rear bucket seat cut a hole on the floor board and pump was out in no time. Best mod ever, I cant believe GM did not install an access door for the pump.

Do you have any pictures? What did you use to cut? Right now its working. How did you patch the hole?

 

[DenaliJJ]

My 04 Denali had similar symptoms. Guage would read 55 with key on and start right up. Shut it off and pressure would slowly slowly drop to around 35-40 after an hour or two. Kept an eye on it for a week and soon it wouldn't start on first crank anymore. Always would the second time. Replaced with a Delphi and it starts right up everytime now. Tank wasn't very hard at all to drop. Some fuel line disconnects and a 15mm socket and you should have it down in about an hour and half at most. Be sure to order new straps and hardware because they are almost guaranteed to strip and spin on ya resulting in cutting straps

 

[Searay45db]

My 04 Denali had similar symptoms. Guage would read 55 with key on and start right up. Shut it off and pressure would slowly slowly drop to around 35-40 after an hour or two. Kept an eye on it for a week and soon it wouldn't start on first crank anymore. Always would the second time. Replaced with a Delphi and it starts right up everytime now. Tank wasn't very hard at all to drop. Some fuel line disconnects and a 15mm socket and you should have it down in about an hour and half at most. Be sure to order new straps and hardware because they are almost guaranteed to strip and spin on ya resulting in cutting straps

Did it leave you stranded or just aggravated you?

 

[DenaliJJ]

Just aggravated me. The pump itself was fine and working as normal. It was th check valve (pressure regulator) bleeding off pressure My suggestion is run it almost out of gas and then drop the tank and replace

 

[ivin74]

Do you have any pictures? What did you use to cut? Right now its working. How did you patch the hole?

See the image of the fuel pump door inside the cab

 

[Searay45db]

My fuel pump went out at 130k and I used the autozone brand and went to shit in 12k miles, had to place it again but the 2nd time I used the oem pump no issues since. I did not drop the tank at all, remove the drivers rear bucket seat cut a hole on the floor board and pump was out in no time. Best mod ever, I cant believe GM did not install an access door for the pump.

Great pics. What did you cut the floor with? How did you seal it back up?