Engine stalls when hot

My car has been running at about 185 deg. with no problems. However, yesterday is was almost 100 outside and as the temp crept up to 200, the engine starts to stumble pretty bad. I had to take it out of gear whenever I came to a stop. Whats causing this, and more importantly how do I fix it? Thanks

 

what kind of car, what kind of motor, what kind of radiator, what temp thermostat.

could be a fuel overheating problem like in my van, or just a regular overheating problem....could need a better pull fan could need a push fan. could be timing related could be carb adjustments

could be a combo of all the above unfortunately. let us know what type of car/motor/rad. etc. and maybe we can narrow it down.

 

64 Galaxie, 302, AFCO Aluminum radiator thats only a few months old,and its big. 180 therm. Fixed blade fan. The car is not overheating, it just stumbles when it gets about 200 deg. My thought was maybe the fuel is getting too hot. Maybe an electric fuel pump? Insulation for the fuel lines?

 

deleted radiator remarks.

 

i had a problem with fuel boiling in my carb. vapor lock type problem. try insulating your fuel line with that cheap bubble wrap stuff first and see if that helps. if it does, make sure your timing is spot on, your carb is adjusted right, make sure your fuel line is routed away from headers, etc. insulate the fuel line good and you should be good to go...WORST possible case if its a fuel boiling problem is get a Moroso "cool can" thats what i did on my van (as theere is NO airflow to the motor/carb at all other than the fan, and routing fuel line is tough not to route it by the headers, etc.

what i did was insulate my fuel line, and ran a cool can,

but...i know timing and carb lean/rich make a HUGE difference as well.

 

if you are running an aftermarket carb and intake,try a phenolic spacer block between carb and intake to absorb engine heat.It may be boiling the gas in the carb at higher temps. causing to stumble.I had the same problem with a 400 Pontiac motor until i made that change.And I am also assuming you have a fan shroud in place to help cooling.Bur my money will be on spacer block.
good luck

 

bttt for more sugestions

 

Exactly!!! This has worked for me many times. Big block+Atlanta traffic in summer= fuel perculation! Don't forget, the carb is on the highest point of the engine, heat rises.