Virtually no difference when 2nd battery connected (As in my Post “Battery Recommendations”).
Do you run a standard starter motor? If so, one of the Brise/torquestarter type starters gives a faster starting rate. Made a huge difference on my crossflow. Good luck in sorting this!
Other random suggestion - Have you checked the ign timing lately? I used to have a high compression 1380 mini that struggled to start if the timing was a bit out (firing too early). It was on points rather than solid state electronics!
#14 Don’t think it’s a problem with timing as this would not affect the starter motor, battery and associated circuitry which I think will be causing the lethargic cranking.
I wouldn't have thought so either but definitely a phenomenon on my mini. The only logic I could come up with was it fired too early while the piston was still rising / compressing and the 'ignite' worked against this almost trying to make the crank go backwards.
When jump starting what happens if you attach the earth jump lead directly to the engine? You can also put the +ve jump lead directly to the starter but you have to be extremely careful.
There is only so many things it can be - faulty cable or component causing a high resistance / poor connection and its a case of substituting one by one.
I've also read of components being tested as good by experts but have later shown to be faulty.
Maybe best to take the starter off and clean the rotor and carbon with brake clean, if it still cranck slow invest in a Lucar LRS110 1.4kw much cheaper than all those special starters and just as good https://www.ebay.co.uk/itm/2-0-FORD-PINTO-LIGHTWEIGHT-UPRATED-STARTER-MOTOR-LRS00543-LRS00109-LRS00110/273796747058?hash=item3fbf8ecf32:g:a~YAAOSw8
That's the one I fitted to my slow cranking crossflow. Vast improvement and lighter too.
Thanks to all. I will bear in mind the starter motor suggested in #17/18. Perhaps even tho the starter motor on the car has been deemed ok one with more power would obviously help. Is the one suggested a pre engaged type as mine is inertia type?
Yes the LRS110 is pre engaged, the inertial type can't match the performance of the new breed of starters, give your starter a good clean and see what that gives. To swap to an pre engaged system can be done on a budget with new starter and ring gear or expensive with new light flywheel, clutch assembly and starter motor.
#20 Thanks. Will take starter off and clean up (although has been professionally tested and deemed ok). There seem to be inertia types, from Transits/P100s which might fit, and might be an option.