Thinking of a 3/4 ton truck

[hacskaroly]

best guess was an out balance problem there is a specific Ohm range they should fall into. if they are too far off from one another then things get kinky.

Yeah, while I ohm'd mine and they were all within tolerance and looked good, I also heard that issues can pop up when the vehicle is running that won't show when off. I bought an o-scope probe that would have let me hold it over each coil pack and look at the wave form produced, from this I should have been able to see if one or more was off, however none of my o-scopes could dial in well enough to see the wave form correctly. Might be a different story if I had a DPO, but all of mine are old-school tube scopes.