No start when at warm temperature Topic is solved

[122sPhil]

I have a boat that has an issue which i htink may be similar to described above. it has a coil for each cylinder. and in that case it also has a trigger.. anyway the cause can be that the coil is encased in plastic, the plastic degrades and it cracks, resulting in the fine wires shifting, one becomes broken ( interittently open)
my old speedboat will go 1 mile from the dock and then die. I think what is happening is that the coil ( or perhaps in my case the coil in the flywheel) has a break such as mentioned. initially it is ok it is closed, runs fine..
heat cuses things to warm and expand then the coil which has a break in a wire , which I cannot see, stops sending a pulse to make a spark.. in my case it is the spark generated within the flywheel, in this case the cars's ingnition system, perhaps.

different parts in a boat ignition system, sure, but I this may be a similar similar "type of" intermittent.

a coil may have many fine strands, one may have a break and be "almost sorta connected" but inconsistent.. heat may cause such a fault to "appear and disappear" as parts grow and shrink..

coil failures in older cars were usually quite rare but possible. offshore ones, I guess they may fail more easily, I assume more plastics are used now. old ones might have been potted in tar. I think the actual cause of this may affect many devices, may be pastic degradation. shrinkage, like how a dash cracks in time. the plastic is not dimensionally stable over the long term. planned obsolescence. the part was designed to work reliably for x number of years. It served its function.

[Pavel9]

Thanks 122sPhil... you have given me a lot to chew on. I'll start by checking connections - grounds. In another week we change over to our winter vehicle, the Rover, so the need to solve this Volvo problem now recedes.

BTW, I had a 1969 122s that served me very well although I remember the under dash windshield wiper motor used to get super hot...

Also notice you are a Vancouverite!