Sorry, deleted original thread about the Minor cutting out or not starting 
when warm.

My money is on the petrol filler cap.  Had exactly the same problem years 
ago.  Blamed the fuel pump initially, as it was seriously hot and famously 
unreliable (SU - similar to yours?).  Had to abandon the car one night, went 
back next morning (surprised to find it still there, including wheels). 
Having thought about it overnight, recalled that I had managed to lose the 
filler cap when refuelling - God knows how - so bought a cheap rubber cap to 
do for the moment.

Anyway - next morning, having wondered about venting, went back to car and 
removed the rubber cap.  Not so much an intake of air - more a mighty bang 
as the petrol tank resumed its original shape.  Large hole bored in rubber 
cap with a penknife, ran perfectly thereafter.

Of course the reason the fuel pump was hot was that it was trying to do the 
impossible.  A herring of the red variety.

So - next time it happens, just take the filler cap off and see if that 
solves the problem.

Good luck,

GMack

Geoff Mackenzie wrote:
> Sorry, deleted original thread about the Minor cutting out or not starting 
> when warm.
> 
> My money is on the petrol filler cap.  Had exactly the same problem years 
> ago.  Blamed the fuel pump initially, as it was seriously hot and famously 
> unreliable (SU - similar to yours?).  Had to abandon the car one night, went 
> back next morning (surprised to find it still there, including wheels). 
> Having thought about it overnight, recalled that I had managed to lose the 
> filler cap when refuelling - God knows how - so bought a cheap rubber cap to 
> do for the moment.
> 
> Anyway - next morning, having wondered about venting, went back to car and 
> removed the rubber cap.  Not so much an intake of air - more a mighty bang 
> as the petrol tank resumed its original shape.  Large hole bored in rubber 
> cap with a penknife, ran perfectly thereafter.
> 
> Of course the reason the fuel pump was hot was that it was trying to do the 
> impossible.  A herring of the red variety.
> 
> So - next time it happens, just take the filler cap off and see if that 
> solves the problem.
> 
> Good luck,
> 
> GMack 
> 
The car currently sports an almost new lockable cap, apparently after 
half a tank of petrol got siphoned out, according to the person I bought 
the car from.  I can certainly try taking the cap off next time I have a 
problem, but surely a cap that isn't cheap ought to be vented, though I 
can't actually see where the air would get in, unless it creeps down the 
keyhole.

Jim

Jim Warren wrote:
> Geoff Mackenzie wrote:
>> Sorry, deleted original thread about the Minor cutting out or not 
>> starting when warm.
>>
>> My money is on the petrol filler cap.  Had exactly the same problem 
>> years ago.  Blamed the fuel pump initially, as it was seriously hot 
>> and famously unreliable (SU - similar to yours?).  Had to abandon the 
>> car one night, went back next morning (surprised to find it still 
>> there, including wheels). Having thought about it overnight, recalled 
>> that I had managed to lose the filler cap when refuelling - God knows 
>> how - so bought a cheap rubber cap to do for the moment.
>>
>> Anyway - next morning, having wondered about venting, went back to 
>> car and removed the rubber cap.  Not so much an intake of air - more 
>> a mighty bang as the petrol tank resumed its original shape.  Large 
>> hole bored in rubber cap with a penknife, ran perfectly thereafter.
>>
>> Of course the reason the fuel pump was hot was that it was trying to 
>> do the impossible.  A herring of the red variety.
>>
>> So - next time it happens, just take the filler cap off and see if 
>> that solves the problem.
>>
>> Good luck,
>>
>> GMack
> The car currently sports an almost new lockable cap, apparently after 
> half a tank of petrol got siphoned out, according to the person I 
> bought the car from.  I can certainly try taking the cap off next time 
> I have a problem, but surely a cap that isn't cheap ought to be 
> vented, though I can't actually see where the air would get in, unless 
> it creeps down the keyhole.
>
> Jim
Probably something like vented down the keyhole. Remember that you 
aren't using fuel at a great rate and temperature changes occur slowly 
so the hole size required for venting is small. Now if you were Nick 
Mann running his old MM with the twin turbo V8 with injection and 
nitrous you might want a larger fuel cap vent. On a similar note a guy I 
know had to his tank crushed on a diesel Ford when the tank vent 
blocked, a common fault IIRC, and the pump kept pumping till it couldn't 
draw anymore, the atmospheric pressure acting on the evacuated tank 
crushed it.

Has anyone suggested checking valve clearances.It is not unknown for gaps to 
close up when hot and keep valves slightly open when hot causing starting 
problem or even non starting.Maybe the seller closed up the gaps to "cure" 
noisy valve gear .Worth checking.
                                        MH
"David Billington"  wrote in message 
news:486e9471$0$2930$fa0fcedb@news.zen.co.uk...
> Jim Warren wrote:
>> Geoff Mackenzie wrote:
>>> Sorry, deleted original thread about the Minor cutting out or not 
>>> starting when warm.
>>>
>>> My money is on the petrol filler cap.  Had exactly the same problem 
>>> years ago.  Blamed the fuel pump initially, as it was seriously hot and 
>>> famously unreliable (SU - similar to yours?).  Had to abandon the car 
>>> one night, went back next morning (surprised to find it still there, 
>>> including wheels). Having thought about it overnight, recalled that I 
>>> had managed to lose the filler cap when refuelling - God knows how - so 
>>> bought a cheap rubber cap to do for the moment.
>>>
>>> Anyway - next morning, having wondered about venting, went back to car 
>>> and removed the rubber cap.  Not so much an intake of air - more a 
>>> mighty bang as the petrol tank resumed its original shape.  Large hole 
>>> bored in rubber cap with a penknife, ran perfectly thereafter.
>>>
>>> Of course the reason the fuel pump was hot was that it was trying to do 
>>> the impossible.  A herring of the red variety.
>>>
>>> So - next time it happens, just take the filler cap off and see if that 
>>> solves the problem.
>>>
>>> Good luck,
>>>
>>> GMack
>> The car currently sports an almost new lockable cap, apparently after 
>> half a tank of petrol got siphoned out, according to the person I bought 
>> the car from.  I can certainly try taking the cap off next time I have a 
>> problem, but surely a cap that isn't cheap ought to be vented, though I 
>> can't actually see where the air would get in, unless it creeps down the 
>> keyhole.
>>
>> Jim
> Probably something like vented down the keyhole. Remember that you aren't 
> using fuel at a great rate and temperature changes occur slowly so the 
> hole size required for venting is small. Now if you were Nick Mann running 
> his old MM with the twin turbo V8 with injection and nitrous you might 
> want a larger fuel cap vent. On a similar note a guy I know had to his 
> tank crushed on a diesel Ford when the tank vent blocked, a common fault 
> IIRC, and the pump kept pumping till it couldn't draw anymore, the 
> atmospheric pressure acting on the evacuated tank crushed it.

Mike.H. wrote:
> Has anyone suggested checking valve clearances.It is not unknown for gaps to 
> close up when hot and keep valves slightly open when hot causing starting 
> problem or even non starting.Maybe the seller closed up the gaps to "cure" 
> noisy valve gear .Worth checking.
>                                         MH

You are right, it is worth checking, but after the more likely 
candidates have been eliminated.  But according to the paperwork, it had 
a 6000 mile service and MOT only 100 miles or so ago.  It is not likely 
that gaps set during the service would need fiddling with after so 
little mileage.

And I have had gaps close on another car (Rover P4) in the past, and 
there was a noticeable misfire on tickover when hot, that could be felt 
at the tailpipe.  I haven't noticed that on the Minor.

Jim