Help with Starting issues *****repost from builds thread*****

[C4UC101969]

Today was a hot - 80F and humid day 85% humidity.

Took the truck out for some simple errands to pick up some stuff at few stores. Stopped at one store for 5min and started back up no problem, stopped at another store for another 5min and started back up no problem. Then I made my last stop and spent about 20 min or so in the store at this point it was getting really humid as it was getting ready for a storm. When I came out and tried to start it back it would turn but not start, I checked my fuel had about half a tank in there, after about 5 to 10 min of trying on and off, the thing just fired right up.

Any thoughts on what it could be?

[geezer#99]

Vapour lock.

[Steeveedee]

Tell us how it is equipped- carburetor, ignition, etc. I see that vapor lock has been mentioned, but that is a pretty low-temperature regime, so I'm not convinced. While you're at it, how did the starter sound? Did it seem to crank slowly?

[C4UC101969]

Originally Posted by Steeveedee

Tell us how it is equipped- carburetor, ignition, etc. I see that vapor lock has been mentioned, but that is a pretty low-temperature regime, so I'm not convinced. While you're at it, how did the starter sound? Did it seem to crank slowly?

Its a carburetor engine stock 307 with 4 barrel, everything else in the truck is stock nothing extra added or taken away. The starter was cranking exactly the same way it did prior to it not starting. I would have to find out from the original owner who did the rebuild (I bought it few months ago) if he used a mechanical pump or electric pump as I am guessing that can also be an issue, after reading some of the forums on here and elsewhere.....

[WorkinLonghorn]

The next time this happens, take off the air cleaner and look down into the carb while you work the throttle with your hand. If you don't see and/or hear gas being pumped into the bores, then you need to look at the fuel filter, lines and pump.
If you do see/hear gas then you need to check for spark. Have someone crank it with a plug-wire off and connected to a spare plug held against part of the engine (or remove a plug and use it). Look for a nice blue spark. If you see a little orange spark or no spark, then you will need to look at the cap and rotor, points and condenser and coil.

Does it start right up in the morning or do you need to crank it a lot? -BA

[C4UC101969]

Originally Posted by WorkinLonghorn

The next time this happens, take off the air cleaner and look down into the carb while you work the throttle with your hand. If you don't see and/or hear gas being pumped into the bores, then you need to look at the fuel filter, lines and pump.
If you do see/hear gas then you need to check for spark. Have someone crank it with a plug-wire off and connected to a spare plug held against part of the engine (or remove a plug and use it). Look for a nice blue spark. If you see a little orange spark or no spark, then you will need to look at the cap and rotor, points and condenser and coil.

Does it start right up in the morning or do you need to crank it a lot? -BA

Thank you for the suggestion I will try that next time it happens.

In the morning with a choke open the truck starts right up no issues there at all, starts really good in the morning.

[El Dorado Jim]

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