Hard to time

[snowball]

Hi all,

I just got my burb running. 1990 350 2wd, and I replaced the icm. I set it to 0. Started and it looked like it was 2 notches ahead and steady. I got on the road started to drive and after about a minute, she started to stumble. Giving her gas caused the truck to shake and stall.

Finally got her home and i looked at the timing again, and she was mostly at 0 but sometimes would jump a lot towards the right, maybe 20' and the whole engine was shacking A LOT!

Any thoughts would be greatly appreciated.