1999 Yukon running rough.

[Jpalmer88]

Out of no where my 1999 Yukon (5.7l) starting running rough, not wanting to start, and wanting to die while idling or in the lower rpms. The engine and exhaust also seem to be what can best be described as chugging. I was originally told I had a bad head gasket and should do a compression test, but told by someone else that it was a bad mass air flow sensor. I managed to get it started and running so I could check the MAF sensor. I unplugged the sensor and it seemed to run the same or slightly better, it also didn't give me a check engine light while unplugged. So as of now I'm at a loss as to where to go next.

 

[lesterl]

Check fuel pressure.

What have you observed besides rough running/ chugging/ hard start? Does it rev good? In gear/ out of gear?

Codes?

Usually unplugging the electrical connector from the MAF is enough to "bypass" it....

Does a shot of carb cleaner into the intake help it start better?