2007 Yukon Denali Struggling to run when warm

[dillpickle1]

my 2007 yukon Denali with the 6.2 Has a P0011("A" Camshaft Position-Timing over-advanced or system performance(Bank1)) Code and a P0420(Catalyst system efficiency below threshold(bank 1)) Code, it also has a Evap Vent valve/solenoid circuit code

The first month I drove the car I came to a stop, thankfully in a parking lot and it sat for a minutes and shut off on me and wouldn't start for another half hour or so, its only ever done it once but anyways, The engine appears to run fine until it is warm, once the engine is warm and you are in drive and come to a stop, it struggles to maintain a idle, as soon as I shift into neutral or manage to get going it stops. I've already replaced the Cam sensor and the VVT Actuator, next I'm thinking its the 02 sensors since it only happens when the engine is warm

 

[swathdiver]

Run a search on the stalling when hot issue, it's been discussed a lot on here over the years but my memory fails me to provide the solution.

As for the P0011 code, what kind of oil are you using? Does it meat GMs standards?

Do you have the ability to read engine parameters such as your Long Term Fuel Trims and the voltage on the oxygen sensors? Need that to see what's going on with the cat. Any exhaust leaks on that side? Triple check.

 

[Geotrash]

my 2007 yukon Denali with the 6.2 Has a P0011("A" Camshaft Position-Timing over-advanced or system performance(Bank1)) Code and a P0420(Catalyst system efficiency below threshold(bank 1)) Code, it also has a Evap Vent valve/solenoid circuit code

The first month I drove the car I came to a stop, thankfully in a parking lot and it sat for a minutes and shut off on me and wouldn't start for another half hour or so, its only ever done it once but anyways, The engine appears to run fine until it is warm, once the engine is warm and you are in drive and come to a stop, it struggles to maintain a idle, as soon as I shift into neutral or manage to get going it stops. I've already replaced the Cam sensor and the VVT Actuator, next I'm thinking its the 02 sensors since it only happens when the engine is warm

As James says, there are lots of threads on this here already. Here is one containing similar symptoms to what you're describing with the evap codes: https://www.tahoeyukonforum.com/threads/2007-yukon-denali-crank-no-start-after-driving.131974/

Long story short, this seems to afflict mostly '07 MY 6.2L engines. Post up a pic of your oil pressure gauge at hot idle when you can.

 

[Fless]

What's the EVAP code?

When it won't start are you using clear flood mode? Floor the accelerator pedal to keep the injectors from pulsing. The purge valve on the engine might be staying open, letting fuel fumes into the system causing an over rich condition. Or perhaps there is a leaking injector which can be identified by performing an injector balance test.

 

[dillpickle1]

What's the EVAP code?

When it won't start are you using clear flood mode? Floor the accelerator pedal to keep the injectors from pulsing. The purge valve on the engine might be staying open, letting fuel fumes into the system causing an over rich condition. Or perhaps there is a leaking injector which can be identified by performing an injector balance test.

P0449 Evaporative Emission control system vent valve/solenoid circuit, its only stopped on me once, over a year ago but I've probably put 150 miles on it in the past year or so, The engine only has issues when warm so something like a leaking injector and such should have affect even when cold?

 

[dillpickle1]

As James says, there are lots of threads on this here already. Here is one containing similar symptoms to what you're describing with the evap codes: https://www.tahoeyukonforum.com/threads/2007-yukon-denali-crank-no-start-after-driving.131974/

Long story short, this seems to afflict mostly '07 MY 6.2L engines. Post up a pic of your oil pressure gauge at hot idle when you can.

Its been awhile since I've worked on this car(and I struggled to find results then but it looks like some new post have come up that i didn't see) now that I'm remembering I do know it had around 80 psi oil when cold idle.

 

[dillpickle1]

Run a search on the stalling when hot issue, it's been discussed a lot on here over the years but my memory fails me to provide the solution.

As for the P0011 code, what kind of oil are you using? Does it meat GMs standards?

Do you have the ability to read engine parameters such as your Long Term Fuel Trims and the voltage on the oxygen sensors? Need that to see what's going on with the cat. Any exhaust leaks on that side? Triple check.

Its been awhile since I've driven the car but if I recall I didn't get any fuel pressure info from the ECU which it should unless that was for later years of that gen, I have no clue whats oil in it, I bought it and drove it maybe 100 miles total and now its been sitting because I haven't been able to figure out whats wrong with it, I'll see if I can read oxygen sensor info. I know my CEL doesn't come on at all either, idk if the previous owner disabled it or what

 

[swathdiver]

Its been awhile since I've driven the car but if I recall I didn't get any fuel pressure info from the ECU which it should unless that was for later years of that gen, I have no clue whats oil in it, I bought it and drove it maybe 100 miles total and now its been sitting because I haven't been able to figure out whats wrong with it, I'll see if I can read oxygen sensor info. I know my CEL doesn't come on at all either, idk if the previous owner disabled it or what

The 2007s that I've seen use relays and the ECM to run the fuel pump and fuel pressure cannot be seen on the scan tool, manual gauge only. The other years have their own computer or share a computer with another component.

Many of those 2007s seemed to suffer from vapor lock when hot but again, it's been a while since I've seen the posts and cannot remember but they are here up to at least 2017 and maybe before.

 

[dillpickle1]

Welp I finally go to starting the truck up and logging some data, I have a complete CSV file if anyone wants it. idk any good CSV viewers so I slapped a terrible one together in google spreadsheets, idk if any of these graphs are useful at all. I noticed my oil pressure gauge displays 80 psi and goes down to like 60-70psi once warm but the ECU was displaying about 34 psi. I also noticed if I rev'd to around 2000rpm for a couple seconds and let off, it'd stay at that rpm and maybe even gain a little rpm and then go down and the idle would fluctuate around 400-700rpm