Vapor lock

I do not advocate a clear fuel filter, but they can be useful in diagnosing things like this, if it is vapor lock it will have no fuel in it.

also when restarting after the 10 to 15 minutes try not pumping any additional fuel into the manifold but hold the throttle open about 1/2 while cranking.


I had a situation where with my stock 273 2bbl the engine would idle then the idle speed would fall off then pick back up. At the same time I could watch the fuel filter go from full to empty then just as the speed fell off it would fill again. Also when the engine was particularly hot from sitting in a fast food line, when I hit the street I had to be super easy on the gas or it would stumble, after a minute of driving it would be fine. I suspected the alcohol in the fuel so I tried non alcohol fuel and all the problems went away and I can not make it happen any longer. i did not change any line routing or add insulation etc.

I fixed both issues by using non alcohol fuel ( Pure-gas.org - ethanol-free gasoline in the U.S. and Canada )