Man, thats a tough one. Tell your boss you need a labscope in the future. Without a scope, it's going to be tough to say definitively if the problem is electrical or not. And even tougher to tell if its pcm
. Also you would want to check the cam signal when it happens, but a volt meter won't be good enough because the signal will change when it misses and the meter won't tell you if it's a cause or an effect. Again, you'd need a scope for that.
But if an entire bank drops at the same time then it has to be electrical. Also if it misses, then runs fine after shutting of and starting, it's electrical, and not likely to be a wiring issue. Wiring can cause intermittent issues, but it's really rare in my experience. Usually the wiring is either good or it's not.
I hate throwing parts at stuff, but sometimes we dont have a choice do we? If I were going to throw anything at it, it would be an idm
before a pcm
. Since the pcm
timing signal is just one wire, i think anyways, it makes more sense that the idm
is the culprit. You could always try a heat gun on the idm
and see if it acts up more, but since it's so random in nature, I'm not sure that will tell you much, but maybe. Get it hot and see if the behavior changes. But if we have to put our money on a part right now, I'd go with IDM
. Sorry I can't help more than that.
Edit: just thought of something. Scan it and watch the pulse widths when it happens. That will tell you definitively if it's a command issue or not.