- Aug 16, 2014
- 32
I recently replaced my 5.3ltr in my 06 envoy Denali. It seems to idle fine for a while then starts to idle rough. It seems every few minutes the computer straightens up problem but eventually goes back to rough idle. The vehicle seems to drive fine on flat land but going uphill under a load it is misfiring and dumping fuel until it won't go uphill anymore. If I turn off vehicle and restart I can go fine again momentarily. So far I have swapped throttle body and fuel rail, installed new plugs/wires, coil packs, and engine coolant sensor but it is still doing the same thing. Any thoughts or ideas as to my next step would be greatly appreciated!!