for the most part its marking where the plug wires are then where the rotor is pointing. ive always just pulled the whole thing then starting from a fresh start as in finding top dead center for number 1 cylinder and going from there.

Ignition Timing for First-Generation GM V-8 Engines

 

Alright, I wanted to give an update. I pulled the distributor, which was in great shape! Anyways I put a new pickup coil in and ignition control module. Set timming, and I keep losing spark. I barely touched the wire harness in the picture attached going from the coil to the ignition control module and she stalled immediately. I jiggled it and then the fuel injectors were just dumping fuel, I had to run and turn the key.I am pretty sure that harness is trashed because I had the kids turning the key and me jiggling it and the truck would fire, then not. Its definitely an issue. I am Hoping all my problems stem from this harness. Will keep you posted, it arrives today.

 

Well, I replaced the harness and the truck is better but still stumbles, just not as bad. I touched the harness on the coil to the left (grey one) and she stalled and lost spark. Took me awhile of jiggeling that gray harness on the coil to get her to fire back up. I am going to order a new one for $10 and splice it in. I have no check engine light or codes so?

 

Before I replaced the gray harness, a few days ago I took a loaded 12ft trailer to the dump, she lost spark as soon as I got to the dump and then while I was unloading the trailer. Took about 20 minutes to get it started again. Like a bad connection issue. I replaced the gray harness and she feels like she had so much more power now. I did leave the truck running for a while, slung some dirt around the house. A few times I was able to floor it from a stop and she sputtered a little bit. Other times it was full power through RPMS. I left it running, popped the hood and pushed the 12inch harness I replaced the first time, going from coil to distributor. I just pushed the wire in the middle of it and the truck died and lost spark. I immediately got in the truck and turned the key and she started up everytime. There is no way that new harness is bad? I feel like this issue is at the coil because of how the wires move. Maybe the contacts in the coil are worn and the jiggle is enough to lose connection? Maybe the ignition coil is bad? I cant make sense of it or where I go from here. I the main engine harness I jiggled while the truck was running thinking its a ground but now I have it narrowed to the wire harness from Coil to Distributor, which I just replaced both ends of it.

 

Your starter should be good. A faulty starter will not cause both issues. I would look at the ignition switch in the column, they fail from time to time. You can test both the crank lead to the starter and the hot wire to the coil with a multimeter or test light to confirm. Because it works intermittently I would think it's the contacts on your ignition switch, on top of the steering column behind the dash. The key operates it with a small rod.

 

So my fault I never followed up with this. I ended up replacing the yellow ignition coil and haven't had a problem with it since. Thanks for all the input. Hope this thread helps someone in the future.