1986 cold start issue 305

[kentrx1]

Been working on 1986 truck with 305. Have replaced fuel pump, carburetor, and plugs. Runs perfect once it starts. If it sits for a few days/weeks have to poor lots of fuel in carb before it will finally stay running. Once cranked will crank fine all day. Suggestions on what I check next?

 

[lifeofbriank10]

I have the same motor with the same type of issue. I as well changed lots of things and nothing made it better. So far my best guess is the engine being old takes time to build enough pressure to start. I do not have to poor anything into mine. It just takes like 10 seconds before it starts and its a really rough start too. It will die right away if I do not keep the rpms up. However, once it gets to a stable idle, it starts fine the rest of the day just like you said.

 

[fast 99]

Carb likely dry, It is common for fuel to evaporate when not driven. However, cranking for a few seconds should provide enough fuel to start. Q jets also have well plugs that can leak. If excessive cranking or priming is required would suspect a fuel delivery problem. Check both fuel pressure and volume. Have seen even new fuel pumps that are defective.

Make sure the choke plate is closing.

 

[PrairieDrifter]

I would make sure the choke is operating correctly first. Ive found if mine sit for 3-4 days or more they lose prime and fuel evaps out of the carb.