Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 don't start when is hot

Hi. In the last period i started to notice this problem with my 3W. After a short drive, like 10 miles, if i stop the engine i can't restart it. Fuel in the tank and fuel pump is ok. What can it be ? After 3 o 4 attempts to start the engine i can smell gasoline so i guess maybe it can be related with old spark plug.
Thank you for your help

Vapor lock?

Hi Ken, what do you mean with " vapor lock " ?
i have like 30% of tank when it happened
thank you for your help

https://youtu.be/xF21UoaLwCk

It can also be fuel evaporating before it gets to the engine if the fuel line is passing by a hot engine.

Hi Neilda, thank you for the link. Tomorrow i'll go again to test my 3W and if it will happen again i will open my fuel tank cap. Today i take off the cooling fan and i found i had a MAP sensor a bit loose. Maybe that was the problem. I'll check it tomorrow. Thank you all for your help

Ten miles is nothing. There is something else. The fuel tanks are in the rear not even close to the engine so heat is not an issue. Worn spark plugs or crap fuel could do it.

How hot was the day?

Another thought: How old is the battery? If it's new then is the alternator/regulator still charging the battery? Easy enough to check with the turn signal stalk. If the battery is old and the regulator is good then the battery can't hold a charge. When the engine is hot, it is much harder to turn over as everything has expanded and compression will be higher. Each cylinder is one liter so that will be a mother to turn over...

It's like a check list. Go through all the symptoms until only one thing is left.

Hi Michael. The day was not too hot, i guess it was like 15 c. degrees. The regulator is ok, i check it always when i use the car. I was thinking about spark plug and battery ( which is like 4 years old ) but when i try to start the engine it's easy to hear it turning well...there is fuel smell but no ignition. I hope it's related with old spark plug. Tomorrow i'll use it again to check if it was the MAP sensor get loose. Thank you for your help

Another possibility, check the spark plug leads where they go under the cowl . I have had some wear cuts on mine which caused rough idling. Since been replaced and rerouted to avoid contact points.

Hi P964. I checked the spark plug leads. It seems all ok. My 3W has no idling problem and runs very fine but just doesn't start when is hot. I'm going out to test it again. Finger crossed. Thank you for your help

If the battery is 4 years old I would suspect that it's nearing the end of it's life. It's probably using all it's capacity now to crank the engine and the voltage will be dropping too low to fire the coilpack/plugs.

Also, do you have the immobiliser? if so this will also stop the engine starting when the voltage drops too low but will still let the starter and all the lights work.

If you can get it hot and then attach another battery via jump leads see if it then leaps into action.