Snorkel Man Lift, no start

[jchipper]

I've got a Snorkel man lift with a Ford LRG-425i Engine, and when the weather is warm is seems to start and run fine. but now in the winter it won't start for anything, I was able to get it to start a few times by taking the coil out and putting it in the oven for 15 mins and then it would start with a shot of ether. so got a new coil and still same problem, also when it's cold there is no spark at all. sometimes when I have one of the plug wires off checking for spark I'll get 1 spark and hear the engine try to start but since I have the wire off it won't start, and then it goes back to no spark. any suggestions?

 

[jchipper]

update: I pulled the wire/probe out of the water temp sensor and warmed it up with my fingers and it fired right up first try then let it run for a min and it wasn't running very good so i put the sensor back in and it started running good so I turned it off and tried to restart and no go, so warmed the probe again and it started but have to put it back in to get it to run right. so this is strange....