As I have reported before, there were continueing problems on the white Cooper with the throttle that would get stuck. After having tried really simple stuff like giving the throttle spindle some extra lubrication, the next step was having a look at the throttle cable. I bought a new throttle cable some time ago at a Mini centre and we planned to put it in today. Since today was also the day for the MSCN beginners technical course at Broek Brittcar in Waalwijk, we went there to have a look how everything was going, and did the job there.
After disconnecting the old cable from the carburettor, the cause for
the stuck throttle was soon found; there was a dent in the inner cable,
just behind the end of the outer cable (big step forward, at least we
are now pretty sure what has been causing this). As the throttle was
opened, this dent would be pulled into the outer cable. The return
spring on the carb would then obviously have extra difficulty pulling
it back than with a perfectly straight cable.
So, we had to replace it. But when comparing the new cable to the old
one and after asking the various technical experts present, we found
that the cable we had obtained from a Mini "specialist" (I did
specifically ask for a cable for a 1991 carb Cooper) was quite useless;
the carb side of the outer cable was completely different, and after
having tried to just replace the inner cable, that was found to be too
short. It was a cable for older types of Mini's.
Luckily, the choice to do the job at Broek proved to be a good one, as
they had a cable for an Austin Allegro in stock which fitted after a
small modification. It is a tad on the long side, but at least it
works.
The throttle returned wonderfully on the way from Waalwijk to Huizen.
However, when I drove home from Huizen to Hilversum tonight, I had the
feeling it was getting into its old habit again. I can probably be
pretty sure tomorrow, when I go to The Hague for a day out with
Demelza, Bertina and Wibo. If the new cable develops the same problem,
there must be a reason for the cable denting at that point. The obvious
answer would be that the inner cable doesn't exit from the outer one in
a straight line.