performance issue

[Kolage]

something weird is going on with my truck not sure what it is maybe timing, I have searched and cant find an answer. Ok here is the issue bear with me its hard to explain. When leaving for work in the morning my truck is cold and I drive about 3 miles before I stop for coffee, by that time my truck has warmed up to operating temp but does not seem to be running as it should. So I shut my truck off and go inside and get my coffee come back out and fire it right up and take off and its running amazing. By the time I get to the next stop light say 1/2 mile down the road, taking off from that light it seems like it isnt pulling as well as it was when I left the store. Same thing happens in the evening when im leaving work and stop to get gas or something. It runs great after turning it off and back on but only for a while then goes back to being sluggish after driving a bit. What does it sound like to you guys?

[zieg85]

First thought to me would be your choke.  Vacuum advance may be hanging up or your ESC not functioning the way it should assuming it has a 305 in it.

[Kolage]

350 hei sorry, has new carb, plugs, cap, rotor, wires, plugs, exhaust. The electronics in the dizzy looked rusted, but the advance things seemed like they opened freely. Maybe I need a new dizzy?

[Kolage]

btw its a 80 gmc seirra classic sorry for the lack of info.

[Jason S]

New carb?  Have you checked the choke to make sure it is operating correctly?  Rusted parts in the distributor doesn't sound well either.

But you could have something as simple as a vacuum leak, masked by the choke. Check the carb to intake mounting to ensure it's not leaking air. Then proceed to check choke adjustments.