84 Toyota pickup misfire all cylinders.
 

Hey guys, I recently put a brand new engine in my 84 pickup. The engine is a 85 and newer 22r. Ran great for a few weeks but I used an old distributor to get me by until I could afford a new one. The old one started having issues where it would run great until it would die after about an hour of driving. (The pickup inside the dizzy made contact with the reluctor wheel points, and there were metal shavings so the air gap was affected). I put a brand new dizzy in and now I have a misfire on all 4 cylinders. The timing is correct, I tried two other distributors, I’m running a gm 4 wire igniter. I tried 3 different igniters and 2 different ignition coils. With each distributor change I adjusted the air gap properly. Using an oscilloscope the signal coming into the igniter is good. But the signal coming out is inconsistent. I have had good luck with gm igniter in the past and I know it works with my set up. I have had a mechanic look at it and he has no clue what to check next. When I crank it to start it, it backfires through the exhaust I’m guessing because I have the proper amount of fuel but not enough spark to burn it all in the cylinders. It was running (like crap) before we started trying to diagnose it but after the new dizzy. But now it doesn’t run at all. Any help here would be appreciated. I am running a Weber 32/36. Let me know if any more info is needed but I think I got it all.