2007 Yukon 6.2 stalls/won’t start when hot

[Campie]

Thanks! I’ll snap some pix later and share. We love the car but as with any used vehicle there are always things that need attention!

 

[Doubeleive]

Thanks! I’ll snap some pix later and share. We love the car but as with any used vehicle there are always things that need attention!

depending on your year they changed the maf design from a screened unit to just a module that mounts in the intake housing in a rectangular slot with 2 bolts.
should be extremely easy to tell the difference. anything after 2008/2009 is just a rectangular module, being it is a 6.2l it may already have the rectangular design but can't say for sure,
pictures would tell a lot.....
looks like there is also option to have a screen or no screen and has a maf module that just clips in with a o ring seal
***this is why you stay away from new design years lol

 

[rdezs]

Also, the Napa Gold filters are made by wix for them.

 

[rdezs]

And I'm thinking your model year has the old style PCV in the driver side valve cover. If so, there's an updated design that's worth getting. Someone will chime in on that I hope.... I can't remember what year they made the change

 

[Fless]

Next time it's a crank-no-start after a hot soak, try using the "clear flood" method. Push and hold the accelerator all the way to the floor, and that shuts off the injectors. While doing that, if it starts after a short crank, an injector is leaking or the purge solenoid (as described by @rdezs) is staying open, or something else is causing excess fuel in the intake.

For test purposes the purge solenoid should be closed (no air getting through it) with no voltage applied -- in the raw -- but open with 12v applied. Polarity doesn't matter for testing.

 

[solli5pack]

Before firing parts at it I would recommend learning how to use the scanner and figure out exactly what's causing the no start condition..installing unnecessary parts could actually bury the real problem even deeper making it more difficult to find...I would start with a purge & seal test on the evap system....

 

[rdezs]

While I concur not to blindly shoot the parts canon at it.....

..... I think that concept needs to be weighed versus this being a higher mileage used vehicle that was just obtained. With that noted, while waiting for a bidirectional scanner to arrive.... I would encourage replacing inexpensive items that are known issues with new. I'm talking spark plugs, wires, mass air flow sensor, map sensor, transmission filter change, serpentine belt, inspect the hoses and make a decision.... Personally on any used car I buy, I always replace the O2 sensors as well. Depending on the mileage and the appearance of the water pump, I often do that as well. And prior to the bi-directional scanner arriving, I would clean and reattach all grounds and check the battery condition and cables. (If the battery cables appear original, we all know that's high on a list for replacement)

These are just basic wear items that one could consider in a complete tune-up per se. It also gives one a good starting point to dig deeper with the bidirectional scanner. I see the parts canon as a problem when you're investing a couple hours, and a bunch of money just blindly going in deep without diagnosing. (Lifters, oil pump, injectors for example)

Some items are worth doing based on the mileage..... Preventative maintenance of sorts. If you do your own work, the oil pick up tube o-ring falls into that category.

The overall condition of the vehicle and what, if any, maintenance records should play a part in the overall plan of attack.

Lol, this is just my two cents on how I approach a high mileage used vehicle. I'm sure everyone has a different approach? For me, I won't let my wife drive off in a new to us used vehicle until I'm 99.9% positive she will not get stranded. (She likes to brag that in 39 years she's never been broke down on the side of the road. So she doesn't question my preventive maintenance methodology)

 

[91RS]

Check that your coolant temperature sensor isn’t damaged. If it is reading a lot higher than the engine actually is, it will cause this. It is very easy to damage and often damaged changing the #1 spark plug.

 

[2 liter beater]

I would probably change your crank sensor. Unfortunately, it’s behind the starter. My new NAPA one came with a lousy o ring that leaked so I did it twice. That exact thing happened to my wife after drive home for 10hrs in triple digits. The starter also failed which didn’t help. Changed both and haven’t had the problem in a year so far. Getting ready for a long road trip this summer so we will seee what happens. Good luck with the troubleshooting.

 

[swathdiver]

This is a very common issue with 2007 6.2s. I don't know what's physically different between them and later years, don't think there is any. However, several people have seemingly solved the issue by wrapping the fuel line to keep it from getting too hot for vapor-lock.

My memory is not so good, the answers are 4-8 years back on the pages of this forum.