Hi,
I have a 1962 2.4 L Mk2 which possibly has only had three owners, 83,000 miles and so very original.
It is very hard to start when hot on a hot day to the point that I raise the bonnet and go for a walk. After say 30 mins starts OK. My research indicates maybe a new coil might fix. The present coild is unpainted aluminium. Would the original coil have looked like that?
Tks
Bill

 

Another question. Is it OK to use the spray "Start Ya *******" in such a case? Is it harmful?

 

i'll bet the problem does not occur if the engine is stopped and restarted immediately. and i'll also guess that the engine needs to be stopped (after being fully warmed up) for a few minute, maybe as much as five or eight minutes before it refuses to restart. if so...

i suspect, like me, you're suffering from something akin to vapor lock, and it has nothing whatsoever to do with the coil or the ignition at all. it's something a bit different and commonly referred to as "heat soak".

the heat in most engine bays of most cars will never be hotter than the interval of time from approximately five minutes after shutdown and continuing for about forty-five minutes thereafter. the reason for this is simple: 1) the fan is not turning, there is no ambient moving through the engine bay because the car is not moving, but the primary cause is that the water pump is not moving, and so there is no coolant moving through the head. ALL of the heat in the head will radiate out into the engine compartment and will heat the inside of the engine compartment to temperatures for which the engine was not designed.

heat begins to build as soon as the engine is shutdown but takes about five minutes for it to become critical, and then another forty minutes or so to fall below that critical temperature again. that's why the engine will start up quite nicely in the morning, run all day, and only experience difficultly in starting for a fixed interval after shutdown.

heat shields don't help, insulated gasoline lines won't help as the problem does not involve gasoline getting INTO the float bowls. timing is not an issue, as the engine is not running and forget about the thermostat, again the engine isn't running and the coolant isn't flowing so it makes no difference whatsoever if the thermostat's open or closed or if it even exists.

under such conditions modern gasoline will partially or completely vaporise in the floatbowl, but most likely in the small conduit between the floatbowl and carb and in the area in and around the jet to a degree such that the mixture becomes too lean to fire when drawn into the combustion chambers.

one thoroughly unsatisfactory solution to getting the car started under such circumstances is to richen the mixture by applying the choke. i find it unsatisfactory because the engine will run very poorly, coughing and sputtering, for about 30-60 seconds while it clears itself of the hot, partially vaporised fuel, before it begins to behave itself again.

i've found the best solution is to immediately open the hood when the engine is shut down so as to keep the engine bay as cool as possible and let th heat radiate out of the head and away from the carbs/floatbowls, when getting gas, or shopping, or stopping for any reason. a better solution, which i haven't tried, would be to fashion a cooling fan, possibly activated by a switch inside the car, aimed at the carbs, not the radiator, when stopped on a warm or hot day. might be worth while opening the hood too.

i have the problem with my MGTD and my MK2. i don't like leaving the hood up, in my MG, as it looks pretentious leaving the hood open as if " on display", and the MK2 just looks plain goofy sitting in a parking lot with a lot of other cars with the hood stuck up in the air. but i've resigned myself to it. as it's even more embarrassing to walk up to your beautifully restored vintage automobile (and people WILL be looking) and have it refuse to start or it starts and coughs and sputters, while you lurch away.

 

As Huey says, it's likely to be heat soak causing fuel vaporisation. The classic solution is some wide open throttle while churning the starter and some blips after the engine starts to shift the vapour.

 

As Huey says. We have all been there on a beautiful hot summers day with people admiring the car until you have to restart it after filling up then it looks as though you have bought a lemon.
One of the joys of owning an old classic car.