2010 Tahoe PPV cylinder misfire

[CrashTestDummy]

Buy a smoker and smoke through the intake and through the oil fill. Might have a vacuum leak.

If you have a rough idle, but everything else is good, I would clean the MAF sensor and replace the purge valve. GM parts are cheap, but labor isn’t. Could also be a bad injector.

I did clean the MAF sensor, and no change, although if it were the MAF sensor, I'd expect it to be a random miss, but it seems to be consistently-posting cyl7. It could be the injector, but I do hear it clicking, and it sounds just like the others.

We have already replaced it for DD duties with a 2018 PPV, so we'll probably try to find this one a new happy home for cheap.

New-to-us 2018 PPV

 

[ndmeilahn]

I know there was a common problem with the throttle bodies, you can try cleaning that. It could be an EVAP leak. It could be a mass air flow sensor gone bad. Check your fuel pressure you could be running lean. It could be a few things, best to make a list and start checking things off.

 

[ndmeilahn]

I did clean the MAF sensor, and no change, although if it were the MAF sensor, I'd expect it to be a random miss, but it seems to be consistently-posting cyl7. It could be the injector, but I do hear it clicking, and it sounds just like the others.

We have already replaced it for DD duties with a 2018 PPV, so we'll probably try to find this one a new happy home for cheap.

New-to-us 2018 PPV

The fuel injector could still be working just not putting out enough gas. If you don't have any evap leaks and your spark is good I would try replacing that injector if that doesn't work do a compression test

 

[ndmeilahn]

The fuel injector could still be working just not putting out enough gas. If you don't have any evap leaks and your spark is good I would try replacing that injector if that doesn't work do a compression

I did clean the MAF sensor, and no change, although if it were the MAF sensor, I'd expect it to be a random miss, but it seems to be consistently-posting cyl7. It could be the injector, but I do hear it clicking, and it sounds just like the others.

We have already replaced it for DD duties with a 2018 PPV, so we'll probably try to find this one a new happy home for cheap.

New-to-us 2018 PPV

One more thing check your ignition coil first. It should be the cheapest

 

[CrashTestDummy]

Truck went to the new owner last week. He's already installed the spare front suspension bits that went with it, and they're diving into the engine issue later. When they put a scanner on it the only thing they could find odd was that the fuel sensor was showing 2% alcohol. We run regular (93 octane) pump gas in the thing so do find that odd that the alcohol reading was so low. I guess that could cause a lean burn issue, and result in a misfire, but it's consistently cylinder 7.

I really hope the issue is simple, and the guy is a friend of mine, so I'll know shortly after he knows.