98 GMC heard I was a Chrysler fan, now this?

I have a 1998 GMC pickup, half ton, 2WD, 4.3 V6 engine. This truck was my every day driver until gas prices went through the roof, and I bought a Chrysler 300. I still have the truck, I just don’t use it any more than once a month or so. My best friend, and mechanic, needed a truck so he is driving it now until he gets his “project truck” done. I have been letting him use it now for over a year, and every time I go get it to bring trash to the dump, haul firewood, or do whatever I decide I need my truck, it won’t run right for me. The best I can explain this, is when I;m driving down the road it feels like the ignition coil is getting ready to quit on me. It feels just like I reached down and shut the ignition switch off and cut ignition to the cylinders. Everything in the cab stays on, all the exterior lights. Just the engine stops, then BANG! The gas in the cylinders gets built up from the sudden shut-off and it backfires back to life. When I bring it back to my friend when I am done with it, he can’t seem to re-produce the problem. He drives it down the road and has no problems for days upon days until I take it again. He claims we have different driving habits. I guess I don’t quite understand why this would make a difference on the ignition coil, but that’s what he insists on. Does this sound right to anybody else out there? (and if so PLEASE explain) Or does this truck just hate the fact that I stopped driving it and basically traded it’s previous trustworthiness to drive a Chrysler product?

Just going through service records, in the past 2 years the ignition coil has been replaced 6 times! I have a feeling there is a different problem somewhere. Is there a ground somewhere that might be bad causing all of these coils to go so quickly? I have tried OEM and aftermarket from all different stores thinking they might be different quality. None of them seem to be any better than the others