Engine misfires after rain storm

[kbryant]

Hi
I have a 2011 Tahoe Q5i 4.3 MPI. Runs great at idle - no issues starting - under a load it misfires and backfires after sitting in a rain storm. I had this issue before about 2 years ago. Shop said it was a loose battery cable. Worked fine for 1 1/2 years until last week it sat in the rain. I’ve just replaced battery and fuel filter and check pickup tube. Anyone else have this issue and some ideas where to begin.

 

[kbryant]

This is an inboard motor

 

[matt167]

New distributior cap, rotor, and wires with di electric grease in the connections.. see if it comes back. It probably won’t

 

[kbryant]

Do you think it will continue to do the same problems after I change those out?

 

[Scott06]

Do you think it will continue to do the same problems after I change those out?

No that why he suggested to replace. Typical symptom of misfire when wet is bad cap rotor and wires. If you don’t know when they were replaced start there. Check your timing and spark plug condition as well.