Turns over, has spark, gets fuel, won't crank!

[Trifling_Milton]

I am at a loss. My 69 f250 camper special (daily driver) was running fine until a couple days ago. It has gotten more difficult to crank. She cranked up fine this morning and I went in to town. When I tried to leave, while still hot, she wouldn't crank. I tried and tried, then the engine finally cranked and was able to drive her home. Now she's in my drive way and won't crank. She fires sometimes, even gets running, but never for longer than a few seconds. Here's what I've done to her in the past year...

new plugs
new wires
new distributor cap
new rotor
it came with an electric ignition (no condenser or points)
new ignition coil
new starter solenoid
new battery
new starter
carb rebuild
timing adjusted

Any ideas of what else I can throw my money at?

[colnago]

Well, I guess that I'll be the first one to throw out a diagnosis. If it only happens when hot, you might be looking at a vapor-lock issue. The carb gets so hot that the gas boils out of the fuel bowls when parked. When you try to restart, no gas. If not that:

- Check the fuel float levels
- Check for output from the fuel pump
- Check for leaks in the fuel line
- Check for water in your oil (long story, and probably not, but it's quick and free)

Joseph

On edit, you said she wouldn't crank. Not turn over? Not fire up? My answers above assume the latter, not the former.

Second edit: What ignition system?

[Trifling_Milton]

Well, I guess that I'll be the first one to throw out a diagnosis. If it only happens when hot, you might be looking at a vapor-lock issue. The carb gets so hot that the gas boils out of the fuel bowls when parked. When you try to restart, no gas. If not that:

- Check the fuel float levels
- Check for output from the fuel pump
- Check for leaks in the fuel line
- Check for water in your oil (long story, and probably not, but it's quick and free)

Joseph

On edit, you said she wouldn't crank. Not turn over? Not fire up? My answers above assume the latter, not the former.

Second edit: What ignition system?

So I replaced the fuel pump and wrapped the metal fuel line from the pump to the carb in case of vapor lock. Nothing worked there. So I popped the top off my carb and noticed there was very little fuel in the float bowl. I poured some fuel directly in the bowl then screwed the top back on. She fired right up, ran for a few seconds and stalled. Couldn't crank it again. I reopened the carb and once again, the bowl is almost dry. I rebuilt the carburetor about eight months ago and it has worked fine until now. What could be the issue? Is it possible that the inlet needle is stuck or something?

The ignition was modified with what looks like an Ignitor brand conversion kit.

[Ohiotinkerer]

Sounds like maybe you have a collapsed/plugged rubber fuel line somewhere since you replaced the pump already - replacing that is something easy and cheap to do and would eliminate that even if it doesn't fix it......also I eliminated the hot start problem on mine with a phenolic spacer between the carb and heated spacer......though I would throw that out there to you if you ever run into that in hot weather - Holley makes them but I'll have to hunt up the part number for you........

[markguiver]

Might also be debris in the tank blocking the pick up. I would start at the pick up and work your way to the carb. Do you have an inline filter? If so, that could be plugged as well. If it is debris in the tank, I would pull it and clean it out well. Kind of a pain but that's the only way to really clean it totally.
Mark.

[Lee]

Hi,

As others have stated... could be a fuel delivery problem.... take the fuel line off of the carb and place it in a container. Crank the engine and see if you get strong fuel squirts into the container. If not, follow advice of others concerning filter, collapesd line, clogged pick up.

Also, as you mentioned,... the float bowl inlet valve may be sticking closed.

Good luck and let us know what you find,

[Mikeincool]

It could be a clogged fuel line. I bought a '67 Mustang that would only start if you poured gas in the carb. I ran a fuel line from the pump into a small gas can and it fired up and ran great. Also it could be bad gas. Either was if you bypass the tank you will know it is not the pump.

[Gray035]

My truck was doing something similar and it turned out to be a bad electronic ignition module. It would run sometimes, and then sometimes it would just shut off for no reason. Mine was a Mallory, which are notorious for blowing modules.