I have an on-going issue with the engine hesitating, just for a split second, under normal throttle pressure. I was having trouble with the Avalanche not starting. The dealer diagnosed the issue as a faulty fuel pump. Since replacing the pump, the Avalanche starts everytime (so far) but once in a while, it will hiccup while driving. Almost like the fuel is shut off for a split second and then back on. The engine just faulters and then picks back up again.
I have replaced the fuel pump, fuel filter, gas cap, Mass Air sensor, & throttle position sensor. No success. The dealer can find no issues with the computer or the electrical system.
Anyone have any ideas where to look?

 

Are you continuing to experience this issue with your vehicle since you last posted, JGF1213? I understand that your local dealership is involved but the issue continues and you are seeking the advice of your fellow forum members to see if you can resolve this yourself. Please keen me posted on the situation and feel free to contact us anytime if you have any lingering questions or concerns.

Jennifer T.
Chevrolet Customer Care

 

Yes, it is still an issue. Vehicle has been to 5 different garages or dealers and more parts have been replaced, but the issue remains.
The latest repairs included replacing the fuel pump relay, fuel pressure regulator, all grounds check out fine. One shop even ran a independent hot lead back to the fuel pump, to eliminate the possibility of a bad connection in the wiring harness. It seemed to fix it, but two weeks later, it had the same issue. Now I am being told to replace the E.C.M. and the cam and crank sensors.

 

I had the same issue on a 2012, I replaced the spark plugs two weeks ago and haven't had a problem yet time will tell if it comes back. I have 60,000 miles on the vehicle.