(I)
Check for slack in the choke cable and that the engine runs at the right FAST
IDLE with the throttle cam in line with the tick mark on the rotating sector
connected to the choke cable,
Check all the things you would in the ignition......., timing, HT leads coil,
condenser, dizzy cap, points gap as per the workshop manual.... the most
difficult engine to start is a cold engine and will show up weaknesses in
components as much as hard revving will
The points wear gradually as do spark plug gaps... is it running ok once it has
started (this is important for isolating the fault).... does it start better
from hot than cold?
Do you have a workshop manual? follow the checks listed in it and you may well
improve normal driving performance AND starting by finding the fault
(II)
(III)
Starting difficulty, check battery terminals
Check the battery terminals for dirt. If they are mucky then starting/charging will be bad, but jump starting (croc clips onto clamps) will be ok, and this often leads to a good battery being thrown in the bin (sorry, taken to you local friendly battery recycling place).
Starting difficulty, loose starter motor?
I experienced this one on a Mk I Ford Escort, not a Mini, but the principle still applies.
I had no joy in getting the thing to start, even though it turned over ok.
The spark was present, but poor, no matter what I did with the ignition system.
Turns out one starter motor bolt was slightly loose, causing the starter to "cock over" slightly and bind, drawing huge amounts of current to turn the motor over.
With all the mounting bolts tight, the spark perked up, and it started first try. Embarrassing, but enlightening.
Paul Sadler ADDED 16 DEC 2002
Starting difficulty, cold weather tip
My Mini (1984 998 Mayfair) used to be a real b*tch to start on cold, damp mornings. No matter what I tried, (new plugs, points, condenser, coil, air filter, manifold gasket, fuel pipes, fuel pump, krypton tuning, etc) it would turn over for ages seemingly not firing - eventually resulting in a flat battery. If it did start it ran like a dream, but it was a lottery getting it to go.
Then my Dad (a veteran of problem starting) suggested that when I parked up at night I pulled the choke fully out. I didn't think much of it as an idea but thought I'd give it a try....IT WORKED! Next morning the thing kicked in straight away.
I've tried this on 2 other problem starting Minis and it's worked on them too.
Starting, solenoid clicks but starter does not turn
If the solenoid clicks, then check:
Somewhere your heavy duty current is not getting through.
Starting difficulty, use of WD40
The famous big mistake. You don't want WD40 *inside* the cap. It insulates and stops sparks jumping. What happens inside the dizzy cap? Just dry it out with a cloth.
Starting difficulty, weak turn over from a good battery
Check the engine earth strap. This is usually a thick cable or braid in the vicinity of the engine steady above the clutch. If this is broken or a poor connection then the current will attempt to take other paths like the throttle and choke cables. This usually leads to slow cranking and difficulty in starting.