won't start when hot

Hi all, this question is on behalf of a mate who has just got a S3 109 saffari, He has servised the carb, changed the coil for a new one, put in new plugs and distributor, it starts and runs very well, drives well etc when cold, but as soon as it gets hot it starts to miss fire then stops and won't start again untill it cools a little, 15mins or so, any ideas??

is it something blindingly obvious that we've missed? :doh:

Thanks for looking.... Nige

Timing ?

don't think it can be timing because it runs a sweet as a nut when cold

Coil not right,put old one back on and try.

tottot said:

Coil not right,put old one back on and try.

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it was doing this when he got it thats why he put a brand new coil on and change the other bits

Try timing it when it's hot - do it by ear, there's plenty of how-tos on the net.

ok thanks will give it a try

I had this on one of my 109's, fuel starvation caused by vapour lock where pipe joins carb.

I just pulled the pipe off, let air out and it be fine again.

ok will try that when its hot
thanks for the reply's

It started when I fitted a kenlowe fan, theory was that as the fan only runs when really hot, there is no cooling air flow over the engine when idling or going slow. I took the fan off, sold it, and stuck the original metal one back, problem disappeared.

Sometimes it's best just to trust the designers I guess

davek0974 said:

It started when I fitted a kenlowe fan, theory was that as the fan only runs when really hot, there is no cooling air flow over the engine when idling or going slow. I took the fan off, sold it, and stuck the original metal one back, problem disappeared.

Sometimes it's best just to trust the designers I guess

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"Oh yeah, it started just after I......." :doh:

There's a lot to be said for "if it aint broke, don't fix it"

oxides said:

"Oh yeah, it started just after I......." :doh:

There's a lot to be said for "if it aint broke, don't fix it"

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Yeah, this was a few years back now, maybe 15, I didn't know any better and to be honest it did make the engine much quieter. We live and learn I guess. It's one of the reasons I won't be taking my viscous fan off the disco or fitting a leccy one.

Sometimes, I think the designers really do know best