Hey everyone, I have a 1998 silverado z71 with a 5.7l vortec. I have unique problem. It seems to be when it is wet/damp/really humid outside, or after a rainstorm… my truck will start and idle fine however when I put it in gear and drive, after a couple minutes of driving it hiccups and misfires like crazy with a loud pop/bang/snapping noise. However it is usually only between 1.5k-2k Rpms and when i drive it for a bit it gets better (unless it’s really wet outside) and it throws no Misfire codes. Also it doesn’t seem to relate to temp (as in warming up or cold) because it will come up to temp and still mis and bang, or it could be fine, and then it rains and i get back in my truck it will still mis/bang. I did a tune up not too long ago including spark plugs, wires, ICM, coil, and dist. Cap and di-electric greased everything and that did not fix the issue. The only pattern i have realized is that it seems to be related to moisture, i could very well be wrong but every other variable seems intermittent or non existent.
If anyone has any insight, please help, i’ve taken this to three shops plus instructors at my trade school and no one can figure it out. Thank you!
If anyone has any insight, please help, i’ve taken this to three shops plus instructors at my trade school and no one can figure it out. Thank you!
