Diesel Bombers - injector # 1 and misfire

hey fellas just looking for some answers on a buddies truck. its a 1999 f350 dually with the 7.3. he said that he can be driving along no issues, hit i decent sized bump in the road then all of a sudden start skipping. says its a dead skip, and it continues to skip until he shuts the truck off and restarts, then it runs fine until he hits a bump again. i dont think its an injector due to the bump its stops working restarts it is fine, im kinda leaning towards a wire under the valve cover thats chafed or a connector that is loose to the injector. he also says its near impossible to start with temps below 40. i dont think that has anything to do with his skip but im an inline guy so just trying to give all symptoms possible. he has a check engine light that comes on after it starts skipping and begans flashing if he doesnt shutoff and restart. i checked codes with a snap on solus ultra and had a stored p0201 inj 1 control circuit low. thanks for all the insight