Canadian Hummer Club Forums

Wow really?  Are these 3.7 engines really so bad?  Seems they have many quality problems.
 
So a little bizarre result.  I switched the ignition coil from 5 to 4 and vice versa to see if the problem then moved to cylinder 4.  I started it up and it ran fine.  Let it fully warm up and not a single stutter in the idle.  I assume the problem will return in some form but for now I'm just going to go with it.

Yes Chad the Head was done around 4 years ago now . It was done at Queensway Hummer owned By Courtesy Chevrolet. Clean the MAF sensor which gets dirty easy and also remove throttle body all the way and clean . It could be a crank sensor and bad coil . If you want ,Maybe contact Courtesy .You never know, GM might even warranty out good faith the head if need be .Doubtful , but who knows ? Also inbox Polar Bear he might know a few tricks !! 

[quote="JSJKU"]
Yes Chad the Head was done around 4 years ago now . It was done at Queensway Hummer owned By Courtesy Chevrolet. Clean the MAF sensor which gets dirty easy and also remove throttle body all the way and clean . It could be a crank sensor and bad coil . If you want ,Maybe contact Courtesy .You never know, GM might even warranty out good faith the head if need be .Doubtful , but who knows ? Also inbox Polar Bear he might know a few tricks !! 
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Well since my ignition coil change everything is running great.  Kind of don't want to fix it if it's not broken.  So I never asked, are you the first owner?

No 2nd owner .

Just a fast fix try gas line anti freeze in fuel ( even WalMart sells it ) cheap also try injector cleaner  both really cheap and will clear "ice" crystalls in the fuel lines for Throttle body see in older section how to Ok its on the bigger V8 but also on it theres a quiet recall on the sensor body on its side on v8 maybe on yours as well.