Here is my shotgun approach.
I had an 84-B2000. slightly different but, these were some of my dramas.

you could have vapor lock.--- a fuel line is close to an exhaust pipe or a hot engine part and while the engine is off the fuel boils and you have a lump of air that wont move.
new fuel pump maybe? if electric it might be a fuel pressure problem force more fuel into the engine than its designed to handle. thereby flooding the engine while its off.
AND since you are already seeing a problem with the rebuild carb, you may have a leak in the float seat and again, your flooding the engine while it sits idle.
Next time you have this problem, pull a spark plug to see if its wet.

Good luck
bobmo

 

Thanks, Bob.

The exhaust system is on the opposite side of the engine as the fuel lines and fuel pump, and the fuel pump is mechanical, not electrical. I believe I replaced the fuel pump when I rebuilt the engine.

I will check a spark plug.

Ron

 

Sounds like the starter is cranking the engine fine, that the engine just won't re-start when the engine is still hot.

I say the thing to do is to check for spark. Use a helper or a start switch tool to crank the engine, and use a spark test tool or pull a plug wire to check for spark. Of course, the starting fluid sprayed into the air cleaner test can readily isolate whether the issue is spark or fuel related.

Recently, I had a bad module inside my distributor on my '88 B2200, was working intermittently. At first I just substituted a part from a used distributor into my distributor to confirm, then just bought an aftermarket distributor. See this topic 1988 B2200 Cranks but won't start

 

Engine Problem Update:

In summary, the rebuilt engine on my 1986 B2000 starts when cold.
Once it is shut off, or dies, it will not restart until at least an hour goes by.

I have verified that there is spark to all 4 spark plugs.
On the advise of a neighbor, I replaced the rubber fuel lines at the fuel tank.

When rebuilding the engine, I put on a new rebuilt carburetor from RodkAuto.
The new carb is leaking fuel at the accelerator pump shaft at the top front of the carb.
When running, there is a lot of dark smoke, so I suspect the carb is way too rich.

Is it possible that the float is not adjusted correctly, or the needle and set are leaking, thus causing the engine to be flooded once it shuts off and not restarting?

Or, does anyone have any other thought as to what my next step should be?

Thanks.
Ron

 

When rebuilding the engine, I put on a new rebuilt carburetor from RockAuto.
The new carb is leaking fuel at the accelerator pump shaft at the top front of the carb.
When running, there is a lot of dark smoke, so I suspect the carb is way too rich.

Or, does anyone have any other thought as to what my next step should be?

As you posted earlier and now realize: you should've gone Weber (same for all you folks whose state's emissions allow that).

Can you return that rebuilt carburetor for refund? You state that it's leaking fuel, tell that to RockAuto.

 

I would definitely check the fuel bowl gas level......when idling.....the stock carb should have a sight glass on it that you can look into......fuel level should be about dead center of the glass.

 

Update:
I tweaked the rebuilt carb and now the engine always starts, even immediately after shutting it off, and the fuel leak is fixed.

I tried to adjust the carb using my very old Sun exhaust gas analyzer. but all I got was inconsistent sporadic readings. Maybe the Sun gauge has bit the dust.
I really have to rev up the engine to get the truck to move from a standing start. Would that mean the carb is too lean?

The shop manual says to adjust the air/fuel mixture to obtain a certain dwell reading.
I don't see how an air/fuel mixture would have any direct relation to ignition.

Thanks.
Ron