Tough "hot starting"

[penstarman]

This is driving me crazy.   I now have two cars that start just fine cold, but won't start when hot.   They'll crank, etc., but won't start.   After they cool down (several hours) they fire right up.   I had assumed vapor locking, but have noticed no excessive heat around fuel lines, etc., plus, two cars now doing it is quite odd.   The only common denominator between the two vehicles (besides being mopars) is they both have mechanical lifters, which probably could use adjusting...but I can't imagine that's the problem.

Thoughts?

[Chryco Psycho]

could be boiling the fuel in the carb & flooding , use a 1214 or 1215 [RB] intake gasket to close off the heat cross over under the intake
the other thing that will help is an insulating spacer under the carb If there is enough hood clearance 

[471_Magnum]

If you live in a metro area that is subjected to reformulated heavily oxygenated fuel, you're probably dealing with vapor lock.

It doesn't take much heat to get that stuff boiling in your fuel bowl.

Unless you regularly drive your car in freezing temperatures, due as Chryco says, block the cross over.

[penstarman]

Thanks, appreciate the help.  Had thought about the gas question, being more prone to vapor lock, but have not had problems w/ my other cars, driven about the same frequency.

Will give it a try.

[NHCharger]

What are you running for carbs? Eddys have a problem with the gas percolating in the fuel bowl after you shut the car off. Edelbrocks only answer for this is a carb spacer to reduce the heat transfer, also what Chryo said about the intake gaskets is a big help.

[Ghoste]

Which is kind of funny seeing as how Edelbrock's sales lit claims the aluminum bodies on their carbs throw off heat better than the competition's zinc.

[gsmopar]

Feel free to correct me if I'm off base here.

You're running a solid lift cam?  What are your initial and total timing settings?  Mopuds with hot cams usually run a lot of initial timing.  A lot of guys advance their initial timing without decreasing the total advance in the distributor when doing the "seat of the pants" tuning.  If any of this sounds familiar I'd suggest decreasing the total advance in the distributor and geting some sort of timing control that retards on startup. 

Later,

Greg