Help! 2007 Denali 6.2

[Joe crooks]

Hi Guys. Thanks for existing here . My 07 6.2 Denali runs like a top... for about 20-25 minutes then starts misfiring and dies. The dying part takes about a minute from start to finish. Replaced fuel pump. Fuel pressure at the rail was about 25 psi too high and thought the pressure regulator inside the pump went. It seems coasting and stopping piss it off once the motor is warm. Once during its four deaths it threw codes p00011 p00172 and p00700. If this issue is already solved can I be pointed in the right direction to the thread ‍ All the best to u all
Joe C from NH

 

[Joe crooks]

Hi Guys. Thanks for existing here . My 07 6.2 Denali runs like a top... for about 20-25 minutes then starts misfiring and dies. The dying part takes about a minute from start to finish. Replaced fuel pump. Fuel pressure at the rail was about 25 psi too high and thought the pressure regulator inside the pump went. It seems coasting and stopping piss it off once the motor is warm. Once after four separate deaths it through p00011, p00172 and P00700. If this issue is already solved can I be pointed in the right direction to the thread ‍ All the best to u all
Joe C from NH

 

[mikeyss]

I would check your mass air flow sensor, check that its plugged in, check wires around the connector. You can check and make sure the intake tube is tight and attached to the MAF, to the intake manifold. 2 of your codes can be coming because of the MAF.

 

[1bdhoe23]

Check your intake manifold for leaks, mass air flow sensor, map sensor and ground wires.

 

[swathdiver]

Hi Guys. Thanks for existing here . My 07 6.2 Denali runs like a top... for about 20-25 minutes then starts misfiring and dies. The dying part takes about a minute from start to finish. Replaced fuel pump. Fuel pressure at the rail was about 25 psi too high...

Howdy Joe. 25 psi too high compared to what? What brand of pump did you replace it with?

Your three trouble codes are quite varied and could mean some sensor is causing the motor to stall once it is warmed up. Did you replace the Cam sensor? That is where I would start. What are you using to pull codes and check fuel pressure, etc.?

 

[Joe crooks]

Howdy Joe. 25 psi too high compared to what? What brand of pump did you replace it with?

Your three trouble codes are quite varied and could mean some sensor is causing the motor to stall once it is warmed up. Did you replace the Cam sensor? That is where I would start. What are you using to pull codes and check fuel pressure, etc.?

Fuel pressure was at 77 psi, ac delco and this was a very cheap code scanner. The first couple times it died and was towed to shop, it hadn’t thrown any codes so they just guessed the pump.

 

[Joe crooks]

I would check your mass air flow sensor, check that its plugged in, check wires around the connector. You can check and make sure the intake tube is tight and attached to the MAF, to the intake manifold. 2 of your codes can be coming because of the MAF.

The maf seemed the easiest to do next. I did open up and examine the old one. Well I at least examined what I could see. The little wires that run across the duct were nice and shiny and seemed to look fine. I did unplug it and plug it back in and examine the harnesses and wiring as far as I could.

 

[swathdiver]

77 psi suggests a restriction somewhere, maybe a pinched line or a bad fuel pressure regulator. Did you replace just the pump or the entire assembly? I would think there would be codes for this high of fuel pressure inside the Fuel Pump Control Module.