Heat Soak Problems at a stop w/ 70 Stang 302
 

The main problem I have with my car (70 mustang coupe, 302, C4, 650 Edlebrock carb w electric choke, Edlebrock performer alum intake, crane cams electronic points conversion, high power coil, Stock breather, K&N filter, 4 core radiator, 180 deg thermostat, flex fan, power steering, front disc) is that when I stop driving at a stop light or in traffic my car runs like crap and will die if I sit there too long. I know it is a heat soak issue but I haven't been able to tune it where it will work. I know an electric fan would help but I don't think it would cure the problem.

My question to others is, has anyone found a solution to this issue with your car?
It can be 110 degrees out but my car will still run at 180-185 degrees thanks to my huge radiator. But my car will still run horribly while at a stop sign if I sit there for more than 45 seconds.

This really sucks and has me considering a fuel injection conversion. Its no fun to drive when you have to have your foot on the gas and brake at the intersection.

Just some guesses... could it be related to the electric choke? When it runs rough have you checked the choke butterfly?
Or if you know it is heat soak, why wouldn't an electric fan work? Although the water temp is at 180, the air under the hood to the intake is getting hotter (esp in that midwest heat!) right?
Is the float flooding or can you size the idle jets down?
Or could it be vacuum related?

I might suggest float level too. When running you might be using enough fuel to run fine, but at idle the float might be too high and you could be too rich. What do the plugs look like? Black and dry would be rich.

was just talking in another thread about vaporlock... do you have a plastic/insulating spacer under the carb? a relatively 'unobstructed' carb (big oval air cleaners look cool, but can trap heat when no underhood airflow)? headers wrapped? late ignition timing (or just not as much vacuum advance as you can get away with)? years ago i'd seen grossly late timing can make exhausts glow red...

anything that traps underhood heat could contribute, either by boiling the fuel in the carb (low bowl level, but rich from all the vapor venting), or just weakening the ignition...

might suggest getting one of those cheep indoor outdoor thermometers, just see what underhood heat does at a stoplight(but might go off the scale)...water temp might be fine, but lack of airflow might raise underhood temps a ton... see if carb body is hot, if fuel lines are run anywhere near headers(not dying though, dont sound like vaporlock in a fuelline) stuff like that.

if you have one of those laser pointer thermometers, might be interesting to warm it up, shoot exhaust header temps after idling in gear for a minute, then add a few degrees timing, just to see if it drops...if so a adjustable vacuum advance might be nice to dial in a bit more timing with throttle closed...I had a big cam in a BBC for a while, had to have the adj vac advance to get any vacuum advance at all...

just bored, tossin around ideas :)