Landrover 90 2.5 petrol starting situation

Hi one and all. I am real Landy nut having just bought my 7th. This time a 1987 2.5 petrol. Lovely and quiet at 50.
I have had this Landy 2 1/2 years and spent loads on the old boy (Joe) Reason for name is that when I bought him, he was multi coloured. LOL
My biggest frustration is that old Joe only fires up when I turn the ignition switch OFF !!!!! He turns over fine for hours but just does not fire until I switch the starter motor off. I have already bought a new low voltage starter motor but this has made no difference.
Electronic ignition fitted now and this has made no difference to the starting situation.
The coil is still the original and has done a faithful job over the last 30 years. Surely this is not my problem as he runs perfectly when started.
I know these engine had starting problems but not like mine. The new engine has done 2,000 miles.

Does anyone have any ideas for me .

Check the plugs are sparking whilst cranking, I suspect they are not.
My guess is the wires are on the wrong terminals rear of ign switch.

Or your ignition switch is busted

Thanks a lot for your advice guys I shall continue my efforts with your pointers.

It is more likley that current drain as you crank the engine goes to low for the ignition system [ coil ] to work.The moment you stop cranking current comes up and off he goes.

Thanks for your comment tottot.
That was a thought that I had and consequently bought and fitted a low voltage starter motor. But that made no difference.
I guess I still have a current drop! Still working on this frustrating situation. At least he still fires up when switching off.

I think I had this on my former 2.5P; turn the ignition key, turns over but didn't fire until key is released from position III.
I was told to check for loose or disconnected wire at the ballast resistor or for a bad connection at the ignition switch or a bad ignition switch.
In fact the problem was solved with a new battery and coil; both were old. I suppose when cranking the voltage will drop below 12V so if the battery is duff there won't be enough oomph.. When the cranking stops, the voltage rises again and you get a spark.

Hi, it is great to hear someone else has experienced a similar problem to mine.
I'll check out the battery first as it is the easiest, but it is turning the engine over fine at speed, so I never thought about it.
I don't know anything about the ballast resistor tho, connections to coil appear and feel good.
Will look into your pointers. Thanks a lot capo.

I had this problem once, the previous owner had wired the switch wrong so the coil was only energised at position 2. Easy fix

Great to hear someone else has had a similar experience.
I'll check out the battery, never gave this a thought as the engine turns over at a decent speed.
The coil connections appear and feel secure but that does not mean it is not a bit faulty.
As for the ballast resistor I did not know this applied to my 2.5 petrol. So a new coil might have to be fitted.
And if that does not sort it - a new ignition switch. Oh well! the joys of defender ownership eh
Thanks Capo for your thoughts on my frustration.

If it's the same problem i had with the switch, just swap the relevant wire on to the other pinout

Hi Kermit, can you be a little more explicit? sorry a bit thick on this.

Ok my ignition switch, there was a wire that went off to the ignition coil. It was connected to the accessories pin, so it only had 12v when you let go of the key. When i turned the key to start, the volts went to zero when in fact the coil should get 12v while the starter is turning as well as in the normal running position
I just needed to connect the wire to the correct pin

There shiuld be an accessory live on the switch which is live in positions 1 and 2- meant for a radio and the heater fan. The ignition coil should be connected to the terminal which is live in positions 2 and 3. It's possible that these two have been swapped over at some point.

Ok gocha.
Thanks Kermit

Thanks for your comment flying Peter
I hope the temperature goes up a bit for me to spend some time checking out the rear of my switch.
No idea how long it will take me to get to the position of being able to see the current wiring configuration!!! Brrrrrr

Check that you have 12V to the coil when you turn on at the ignition, and it's still there when you crank.
If you haven't, put one in from the switch.
I had a similar 'problem' with my Series I after a 'professional' main stealer fitted a new coil!

Ok thanks for that oldseadog