I bought an 85 C4 and it ran great for about a week. It started running really rough and giving me a code 33 (MAF sensor) I replaced sensor but still coding. I pulled the MAF burn off module from under the dash and it seems to work fine. but now engine won't start at all. after doing some more testing I discovered the timing was off. I opened timing chain cover the sprockets show some ware but hasn't jumped time. I pulled the distributor cap and rotor was 180 degrees off. I then pulled the distributor and the gears look good (no sighs of ware). I'm stumped ! What could be causing my distributor to jump?

sheared the pin on the gear?

When the dots on the timing gears are lined up closest to each other the engine is in FIRING POSITION #6!!!!!