Could this be fuel vaporisation due to high temperature under the bonnet. You might be able to check this by reproducing the fault on the road, then immediately spraying carb starter fluid into the air filter and seeing if starts immediately (it should then falter and stop quickly as the carb starter will only last for a few seconds). Rerouting the fuel lines or putting some heat insulation on them may help.
If the vent hole in the filler cap is blocked, it might be that a partial vacuum is building up in the petrol tank limiting fuel flow (which gradually goes away after a rest).
I think the coil should get warm but should not be too hot to touch. Does your car have a ballast resistor in the low voltage feed to the coil? If this has gone short circuit, the you may be running a ballasted coil (which expects 7-9V) at the full 12V which will certainly make it hotter. You can test if you have a non ballasted coil by measuring the coil resistance. It should be about 3 ohm for a non ballasted 12V coil, or about 1.5 ohm if it is intended for use with a ballast resistor. (The use of a ballast resistor was normal in 72 I believe).
If you haven't changed the plugs and plug leads I'd do that too, as it won't cost much.
Last edited by SCX358G; 20/05/24 01:40 PM.
