Wanted to let everyone know that my '86 pickup was starting and dying quickly after. Touch the gas after start, dies quicker. Spray carb cleaner in intake (bad for cylinder lubrication) and it will stay running until carb cleaner stops.

Solution. This time it wasn't an AFM-COR issue or broken belt. The EGR valve was stuck almost completely open (about 60%) making a massive air/fuel ratio problem immediately after start. Touching the gas would open the throttle which would lean the mixture further before fuel could catch up causing death sooner. Didn't find this solution so I'm posting my fix. Temporarily deleted EGR with LC engineering plates until I can repair/ replace EGR.