Fuel supply troubleshooting

[bhsdriller]

Have an issue where it acts like i'm running out of fuel while driving.

It ran fine on my way to work in the morning when it was colder, no issues. Left for lunch drove a couple miles and on the way back it started, so seems like it's only when warmer out.
It starts bucking and surging then it will completely die. I can sometimes barely feather the throttle and keep it going in first but eventually it will still die.
Check the fuel bowl right after and it will be empty or low enough to where it's not in the window.

I'll wait a few minutes and it fires right up, idles fine and I can keep going for a few miles then it starts again.

Have replaced fuel pump and filter. Tried connecting the idle solenoid directly to battery + and - with no change. I took the fuel cap off and it seemed to help a bit but still happened.
Vacuum at idle is 20, no issues there will idle all day

 

[bhsdriller]

Seeing some threads on vapor lock but is that only when it's hot out?
Possible blockage in fuel supply line?
Charcoal canister?

When I say it's happening when it's warmer it was maybe 75 degrees when it happened.

 

[CruiserTrash]

Lots of possible culprits: vapor lock (I think this is more rare than folks think), float valve gone bad, vacuum leak when opening the throttle, internally leaking accelerator pump (swamps intake with fuel and runs through your float bowl reserves quickly). Still could be supply issues like you're thinking too - crud in the tank loosening and clogging the fuel filter (even a new one), fuel pump was iffy right out of the box (rare), clogged/corroded fuel line.

Does the vacuum nose dive as soon as you open the throttle?

 

[bhsdriller]

That I don't know my gauge is under the hood. I'll have to route it into the cab and check.
Or I can just test at idle I guess with my hand operating the throttle

 

[CruiserTrash]

That I don't know my gauge is under the hood. I'll have to route it into the cab and check.
Or I can just test at idle I guess with my hand operating the throttle

Does it stumble opening the throttle by hand, or only under load while driving?

 

[bhsdriller]

It does not and I can start it and drive fine, rev it out no problem for the first few minutes before it starts

 

[bhsdriller]

Have an update. Vacuum was lower than I thought so the insulator plate got replaced at the same time. Was down around 16" and now up to around 20". Some vacuum line fixes probably helped also
Blew out all fuel lines
New pump and fuel filter
Went through carb completely and cleaned it while it was off
Fixed some vacuum lines that were routed wrong

Drove it and seems to be fixed so could have been a combination of it all but running better than ever