I have a 86 d-21 with a 3.0 v-6. Sometimes when you go to start it it will be very hard to start and you have to keep it running by giving it gas it may do this for a couple of miles then smooth out and run good but you can smell gas like its flooding. It has a carb not aa throttle body
When cold, the choke plate should nearly be closed the entire way. If it is closed the entire way, it will draw too much gas. It should be open slightly and remain that way until you kick it from high idle. Remove the air filter cover and check it when cold.