[cu42]

I finally finish a restoration on my 1984 Chevy C-10, I have been road testing today and noticed that after driving the truck for about 20 or 25 minutes and turning off, to buy food for my dogs, I had to cranked more than normal to bring it back to life.I turned off a couple more times before getting home and the same thing happens. Even I did not smell gas, neither the carb shows any overflow, I had to floor the gas pedal every time I had to start the engine. This did not happen when truck is sitting overnight and I turn it on. This truck doesn't have the emissions control system from factory. Charcoal canister was eliminated and the fuel return tube was capped, same thing with tube to the charcoal canister. The stock fuel pump was substituted by an Edelbrock "Victor" Fuel Pump, 110 gph- high volume that produces 6 psi and doesn't require a regulator. The engine has also an Edelbrock 600 Performer Carburator and intake manifolds. Any similar experience with fuel pump and carburator similar to mine? Thank you for your comments.
Luis

[carsavvycook]

You most likely are experiencing a vapor lock problem.

With your vapor line at the cannister capped, and the non-vented gas cap, your fuel tank will be in a 'vacuum' stage when the fuel is hot. Your fuel pressure may only be 3-4psi at this point, and when the fuel tank vacuum decreases over night, it will start up no problem.

I know this from trying to get a Toyota Celica Supra to pass the emissions test here. It failed the EVAP leak test, and the owner put a clamp on the vapor hose back by the fuel tank. The suction was enough to partially collapse the fuel tank, and cause a no start/run situation.

[Gringo]

Or your float could be set too high or your needle and seat might not be holding the pressure

[Furytom]

It could simply be a boiling fuel issue. Very common with the this times gas and a carb. If your car is hot the fuel can boil. Boiling fuel can not be pumped or metered and so your car will not fire. I just red a tech article about that in the current mopar action magazine. They suggest all kind of corrective actions to fix that issue. For example replacing the machincal fuel pump with an electrical use a non diaphragm pressure switch, reroute fuel lines away from the heat source and insulate them and so on. I can type in the whole answer if you feel that could be your issue. Or you just have a look at the magazine yourself.

[johnnya]

If I remember correctly, AFB carbs (That's what an Edelbrock carb is) when used on mid '60's Chevys had a phenolic spacer between the carb & the manifold to keep the heat away from the carb base. It might be purcolating while it's sitting.
What you describe sounds to me like fuel entering the engine while sitting and giving you a flooded condition. When it sits overnight it gets a chance to dry up.
JA

[cu42]

Thank you guys for all your imput, I will check the carb tomorrow and will let you know once problem is solved.
Thanks,
Luis

[T-bucket23]

It sounds like you choke is closing to soon. Is it an electric choke. When it happens get out and look at the choke, I would be willing to bet it is closed. Electric chokes in most cases dont know the engine temperature so if you shut the car down for 10-15 minutes, it is possible to end up with a warm engine and a closed choke. This will cause a hard start for sure. If this is the case you may be able to back the choke adjustment off so it wont close so fast.

[cu42]

Finally I had the time to start playing with my truck again, T-bucket23 you were right, mine has an electrical chock and it was too much closed...I just turned few degrees counterclockwise and the problem was solved. Thank you to all of you guys.
Luis

[T-bucket23]

Glad I could help, and thank you for posting back. It is very frustrating to help someone and then they just disappear and you never know if the issue was resolved.

[Carlos9]

I have the EXACT same problem with my truck on a recently rebuilt engine. Not even 500 on it yet. I will have a look at the choke this weekend after it's been running for a while. I should have thought it was probably something like this (same carb, dist, used). I was thinking my dist. was faulty.. or someone told me I did not have enough cranking power in battery. Funny though, I paid a friend to tune it last week. The timing was so on (still is, I have not moved it) it fired before you could get the key all the way around. We never drove the truck anywhere.. so we thought we had it fixed. I drove it the next day, then tried starting it immed. after a long trip and exactly what you are describing.

I'll have a look at my choke this weekend. I have a quadrajet manual choke. Maybe it's doing the same thing.