Triumph Repair: what else - TR6 overheating, fuel pressure gauge, water pump impeller

Question
Cooling system, timing, and carb muixture..the trinity of overheating sources.

I have a 74 TR6; I have flushed the system, replaced hoses
(including the heater hoses at the firewall, replaced thermostat, new water pump, new radiator, timing is 4 ATDC, and the carbs are adjusted. The vehicle overheats everytime I stop at a light and then is overcomed by what I beleive is vapor lock..in other words the engine seems to choke and hiccup as if it was not receiving enough fuel. Once I wait a few minutes it will start and drive normal once again, until I stop idle for a few minutes.

Any suggestions will be greatly appreciated.

Thanks,

Steve

Answer
Hi Steve,
The symptoms you describe narrow your problems to a hundred possible so you must do some testing.
First is the overheating. You must confirm that it is really overheating by checking coolant temp with a thermometer in the radiator at idle or see if it is boiling over at idle.
When any engine overheats at a stop it is either no air going through the radiator or the water pump impeller is not turning or a lack of circulation for some reason. All engines produce much more heat at cruise than at idle so if it only overheats at a stop at idle then check circulation, fan and coolant level, etc. Even though timing and carburation can cause overheating it would show up more at cruise than at idle.
Overheating can cause the fuel to boil in the lines to the fuel pump and even in the fuel pump. This can be easily tested by installing a "T" in the fuel line between the pump and the carbs and install a fuel pressure gauge. Than watch the gauge when the engine falters. If you have a vapor lock it will show up then. Also, check to see that the float chamber vents are open.
let me know,
Howard