Will not start after running for a while

Hello everyone. I recently purchased an older motorhome/camper van and after I run it for a while and I shut it down, it will not start until it has sat for a while.
It is a 1986 Ford Econoline 250 XL, 5.8L engine with a 4BBL carburetor. The van runs great once it starts and it will start right up again if it does not run long. The problem only occurs if it runs for a longer period of time. Thank you for your help.

when the starters get old they distort and bind up when they get hot, it seems like the battery is weak because they will barely turn over. once they cool and the metal contracts again, no problem. at least that has been the case with my fords with 360 and 390 cu in motors

The problem might be vapor lock.

Vapor lock occurs when the fuel in the gas line above the engine starts to boil.

The fuel you’re using probably contains ethanol. And ethanol in gasoline makes this problem worse.

Carry a bottle of water in the vehicle. And the next time you find the engine is hard to start, open the hood and pour the bottle of water over the fuel line and then try starting the engine. If the engine starts that’s vapor lock.

Tester

What exactly does it do when you try to start it? Does the crankshaft turn, but the engine not fire. or does the crankshaft not turn at all?

Thanks all. Will definitely try the water test next and will keep my eye on the starter. When I try to start it, the starter seems to work fine and engine turns over okay. Sometimes if I pump the gas pedal quickly, it will catch and start up. When the engine is cold it starts with no issues at all.

yeah, if it does not sound like it is straining when you re start it, it probably is not what I suggested. sorry

It’s an older vehicle meant to be on the road. So you might as well start collecting a box of essentials and basic roadside troubleshooting tricks now. For a full cranking no-start you probably lack fuel or spark and you can generally find out which.

At an auto parts store pick up a spark tester and a can of starting fluid to keep around. Starting fluid substitutes for fuel, and blown into the carb will tell you if you have a fuel delivery problem. The spark tester is an easy way to find out if the ignition system is sending spark. Tester’s water trick is a fine thing to have in one’s arsenal of tricks for fuel problems.

Since it’s only happening after long drives and not when cold, my guess is going to be that you have something in the ignition system becoming heat soaked. When you shut a vehicle off, the underhood temperature rises measurably. You no longer have air passing through the underhood area, you no longer are pumping coolant through the engine, and the engine’s intenal temperatures radiate outward (along with the cooling system components) and raise the temperature under the hood. Since cylinder temps can reach over 2,000F and the engine operating temperature is over 200F, everything around the engine gets heated up beyond what it sees when the vehicle is operating. Anything becoming heat sensitive will fail under these conditions until it cools down again.

Cig’s suggestion to test the spark as well as fuel delivery is a good one. Since this vehicle uses spark plug wires, you can also use a timing light with an inductive pickup if you have one to test for spark. Hook it in, and check for the timing light while someone tries to start the vehicle. No light means no spark.

truck does not like hot restarts. try leaving hood open after you stop. see if that makes any difference in starting. i would look at heat sensitive ignition parts. coil, ign module, plug wires, and such