My flathead in a 1952 F-1 cranks right up cold.When it gets hot and is off for about 15 to 30 minutes it is very hard to start.If I just turn it off,it will crank back up it just has to sit for a while for the hard starting problem.I don't think it is the carburetor leaking down.What should I check? Thanks,Russell

 

When a weak starter gets hot from normal driving temps it can pull more curent and not rotate fast enough to start the engine. I would recomend rebuilding or replacing the starter after cleaning all conections.

 

There's also such a thing as vapor lock. I hate to even mention those two words.

 

The starter turns it over fine it just won't fire right up.I have to grind on it a little before she fires up!What can be done about the bad word vapor lock?

 

Vapor lock was a very common problem once. Basically it has to do with placement of fuel lines/fuel pump and heat. The fuel vaporizes in the pump and/or lines. Old time methods to cure vapor lock were clipping wooden clothes pins on fuel lines, wrapping the lines in aluminum foil, wrapping the fuel pump with a damp cloth, installing an electric fuel pump, adding a shield to deflect heat away from the fuel pump. The electric pump worked the best.

 

It is all stock and nothing been changed around since 52.Did they have this problem back then?I have not tryed another coil yet.Could that have something to do with the problem?

 

Yes ALL vehicles had the problem once, and it's still with (some of us) today.

Never heard of a coil causing vapor lock. But I have experienced it, more than once, on many old rides.

 

I don't believe in vapor lock so it never happens to my rig.

Seriously, in 6 years as a daily driver I haven't experienced a single instance of it. I think it may have been more of a problem in cars where the engine compartment is confined, but a truck has plenty of room for air circulation and the fuel line doesn't have to get close to the exhaust manifold.

If your truck is stock, try pulling out the choke when it won't start. That will suck fuel from the tank IF it has vaporized in the pump and carb bowl.

Or try holding the gas pedal on the floor while you crank it over in case it is getting too much fuel.

What is the condition of the carb's power valve? One backfire will rupture the diaphragm and the fuel bowl will drain into the intake manifold as it sits. I doubt this is your problem tho, since it starts ok cold.

Weak coil or condenser could also be the culprit IMHO, but has nothing to do with vapor lock. Just not enough spark to ignite the gas in the cylinders. Heat causes them to fail.

 

I had vapor lock on my truck, but it was because I did not have the exhaust hooked up yet. The manifold was blowing right on the fuel line. I now have the exhaust on and have not had a problem.

 

I am glad I came through this thread, cuz I need you to see my similar situation and give me a clue:

My 66 Ford F100, I-6,300 with 1 brl Carter electricchke carb ( It is for 1984 F150). the truck starts fine when cold but it wont start easly when hot, the exhaust control is deactivated. The ciol is new installed, and I rmoved the carb inlet filter due to clogged and I cannot find a replacement.
I wish someone could tell me what is wrong. Thanks.
Hamid

 

Well,I got my starting problem solved!I just bought this truck about 3 weeks ago and the owner told me about the hard starting before I even went to look at it.It was hard to start and I bought it and drove it about 75 miles home.After checking everything over and over I finally figured out the battery was hooked up backwards!!!!!It cranks right up now.It seems like the regulator and generator are ok.I thought maybe something else could have got messed up with the battery hooked up wrong.I could not believe the truck would even run!

 

So it's positive ground then? Right?

 

Yes,it is positive ground system.I did not know that the truck would run either way though!