Good morning Silasyac,
Welcome to the GMT400 forum. There are a lot of folks in here who share a
deep appreciation for how this generation of the General's trucks look, run, and
work. Big bang for the buck, if you know what I mean.
But before anyone here can hazard an informed guess as to what's ailing your
vehicle, we first need to know the year, model, which engine/transmission/rear
end gearing/tire size, whether the vehicle is stone stock, or has it been modified
over the decades?
For example, troubleshooting the ignition system on the '88-'95 TBI versions of
our vehicles is different than the '96+ Vortec versions. Actually, it can be quite
a bit different once you start chasing cam (distributor) <> crank phasing, resulting
DTCs, etc.
In other words, help us help you. Pretend that we are sitting in closets, and we don't
see anything that you don't share on the screen. Photos really are worth a thousand
words, especially when looking at the underside of a distributor cap and looking for
a failed electrical pathway or carbon tracking.
Please reply with the requested data, and I'm sure that someone who's solved a similar
issue in their own engine bay will join in and help you keep your GMT400 on the road.
Best of luck with the troubleshooting hunt.
Cheers --