Is this the dreaded 914 vapor lock?, Asking for your ideas and thoughts Options

[Artfrombama]

Drove my 914 to a PCA function yesterday morning, 93f and humid.
After driving on the interstate at 70-75mph for around 45 miles I exited and the motor died. I had enough momentum and coasted into a gas station/convenience store where I topped off the tank and tried to restart the car, no luck. The car would fire, run a few seconds and die then refused to re-start for another 10-15 minutes then the same scenario again. No tools to diagnose or repair.
While waiting on AAA for three hours (another story) I would occasionally try to start the car with the same results.

Today, car started normally, runs normally.

1974 L-jet, original three bung fuel pump, original location.
500 miles on new tank, sock, filter, ss lines.

[emerygt350]

Yep, sounds like vapor lock to me. I have mine all in the original locations and wrapped it in high quality heat wrap. Haven't had a problem since. I can tell it still thins out when I park it on a day like you describe but it starts up and goes fine after 5 seconds of pushing new fuel. Before the heat wrap there was nothing I could do but wait.

I was racing today on black tarmac 90 degrees, started up all day under extreme conditions.

Is it design engineering? I can't remember but everyone uses it.

[Artfrombama]

Yep, sounds like vapor lock to me. I have mine all in the original locations and wrapped it in high quality heat wrap. Haven't had a problem since. I can tell it still thins out when I park it on a day like you describe but it starts up and goes fine after 5 seconds of pushing new fuel. Before the heat wrap there was nothing I could do but wait.

I was racing today on black tarmac 90 degrees, started up all day under extreme conditions.

Is it design engineering? I can't remember but everyone uses it.

@emerygt350 thanks for responding
Vapor lock came to mind right off the bat but after an hour or so of not starting I started to suspect other things.
As I mentioned, today runs normally.

[wonkipop]

Yep, sounds like vapor lock to me. I have mine all in the original locations and wrapped it in high quality heat wrap. Haven't had a problem since. I can tell it still thins out when I park it on a day like you describe but it starts up and goes fine after 5 seconds of pushing new fuel. Before the heat wrap there was nothing I could do but wait.

I was racing today on black tarmac 90 degrees, started up all day under extreme conditions.

Is it design engineering? I can't remember but everyone uses it.

@emerygt350 thanks for responding
Vapor lock came to mind right off the bat but after an hour or so of not starting I started to suspect other things.
As I mentioned, today runs normally.

interesting that it shut down as you exited.
not quite the usual vapor lock syndrome. that tends to happen after you stop and leave it for a bit. (i have always believed more than anything that is due to radiation from the magnesium fan shrouding. its a heat sink for all the engine heat due to metal heat flow conduction from aluminium case and iron cylinders etc).

it could be that your fuel line is collapsing somewhere along its length. possibly in the loop under the fuel tank or even in the looping into the fuel pump. coming off throttle at cruise. trying to think what the pump is doing. fuel pressure would back off and be sent through the return line via the fuel pressure regulator and return to the tank. this can upset the draw perhaps on the fuel pump. i'd say its something like that. as if the fuel supply line has collapsed. after a very long period of time the vacuum lock in the line releases and its all back to normal.