Morning,
I'm off work today but have some I have some other things to do. If I get chance, I will try the separate feed and report back.
When we tested it on sat, we used the dizzy I bought from Powersaprk, he didn't try another one. However, we did swap in a new module, which is sat in the dizzy at the moment.
As far as the battery voltage under off load conditions is concerned. The 12.7v shown at least proves the alternator is working, which the mech tried to suggest was at fault.
If I was getting low volts under starting conditions, wouldn't that show up under all starting conditions not just no turn over with dizzy advanced? For there to be a volt drop wouldn't something have to be using that voltage? another component or a bad earth perhaps? When my alternator was packing up, I thought it was a bad earth so I went mad and fitted three new earth straps (as well as the remaining straps) Plus there are only a handful of electrical systems running on this car (it is only a mini don't forget) what could be causing the drop?
12.7 doesn't show the alternator is working - Mitsubishi alternators for example can have a diode pack break partially, causing AC to be injected to the ECU causing all the warning lights on misti ECU'ed cars to illuminate.
You could find a battery that wouldn't pull the socks off a dead man still reading 12 plus volts at rest.
If you were to ask the Captain the best way of moving forward, I'd suggest that you tempt the wife out the house with a Mars Bar, pull the coil HT lead to stop it starting, then get her to crank it for just a second or two while you check voltage at the battery - if that's still good, grill off and repeat the test between block and starter main terminal, and see what sort of difference you have, if anything.
I'm going to stick my neck out and say that if you have much less than about 10.5 volts at the starter then electronic ignition could be doing very odd things - I'd also say that you could do to find the cause of that voltage drop.
I'd also ask powerspark to confirm what is the minimum stable voltage that their system can tolerate is. Remember that if you see 12.7 on a meter, doesn't mean you get it - I use a meter with built in data logging so I can record max and min, if not the built in smoothing and anti ripple makes it impossible to see exactly what is happening while you crank.
As you've seen, the thing can run OK when it gets the right amount of volts, but we don't know what the minimum is, powerspark don't have that info, and we do know that if the thing gets the wrong amount of volts, the timing goes all over the place, making cranking voltage drop even more.
Edited by Captain Mainwaring, 04 July 2013 - 10:22 AM.