Vapor Lock On A Beautiful NW Summer Day

RustyRatRod said
Have you verified it is vapor lock? True vapor lock is pretty rare......even with ethanol in the gas. The more ethanol, the easier it is to do it though, so if you have more than 10%, that might be what it is.

That's my best guess. The fuel filler cap is a rattle fit, new fuel filter, and I drove real hard (extended high RPM) before the valve job trying to blow out 20 years of carbon from the previous owner driving it to the beach front each summer.

I've had an ignition coil overheat and short out. It didn't act like that.

In a previous life, I was lucky enough to ferry GA airplanes around the country for a local Cessna dealer. One I ferried from the factory was a Turbo 206 that needed a fuel boost pump before landing to prevent vapor lock. The engine would lope and die if the fuel boost was shut off before the plane was parked when the engine was hot.

Driving the Dart back to the barn with the wet rag, "farm fix" it cruised without surging, but died at every down / up shift (letting off the gas). I've idled this engine a fair bit since purchase and it's never died until this hot day drive.

Ethanol in WA state must be 10-15%.

Naplm00 said
I had the same exact thing happened to me when we picked up our car last year. Was a 100° day.

I did the fuel line mod and added a carb spacer. I also added a reflective heat wrap on the new rubber line. in the long run I think I'm going to change it to something else because I really dislike the fuel line going over the valve cover.

It was effective in eliminating vapor lock it's just unsightly and a pain in the *** when you want to remove the valve cover.

Almost likely be doing another hard line from the fuel pump along the engine where the spark plugs are around the back of the motor and then to the carb.

If you do add a spacer underneath the carb you'll most likely have to upjet as I did.

My spacer came in a carburetor rebuild kit from Mike's carb parts didn't have to pay extra for it it was already there.

I'll keep that carb spacer in mind if the fuel line reroute doesn't completely cure the problem. I wondered too about the routing over the valve cover. The heater core hoses were short enough that I had to pull those to adjust the valves. Pain! After I finish rebuilding the heater box, I'll be looking at routing heater hoses like RustyRatRod did on his.

Thanks you guys!