since yesterday my truck when i go to take off from a stand start normally it will have a sort of mis where it loses power when a cylinder fires. like its not getting spark. its only happened below 3000rpm.

i thought it might be the spark plugs so im gonna change them 2day. and maybe the battery.

but it doesnt have any trouble starting up. bad plugs? plug wires? but the battery light on the dash is whats got me thinking something else.

AND WHEN IT MISSES IT GOES RICH like 12.9 : 1 in closed loop only when it misses so you think a cylinder is miss firing?


thanks alot guys.

 

I had the same thing , #1 plug heat shield was resting against the exhaust manifold causing a miss fire

 

cool thanks guys.

 

Exact problem I had on 2 of my trucks. That would be the first thing I would look at. Probably a bad wire because of it.