Hi,
I would appreciate any tips you might have on the following. My 85 SD1 VDP runs on LPG and/or Petrol. This morning I started it on LPG and backed out of the garage. When I tried to start it after closing the garage, it would not fire. I switched back to petrol and waited for about 20 minutes and then tried it again - to no avail.
I know nothing about electrics, but can confirm that I do have 12 volts at the coil. Nonetheless, it seems like it is not firing the plugs - just keeps cranking over.
The battery has been run down somewhat with all my cranking so I have put it on the charger for the night.
I reckon it has to be an electrical fault, but am wondering what could just "go" like that without any notice.
Any advice appreciated.

Regards,
Paulcnb

Hello Paul,

First establish if you have a spark at all the spark plugs.

If yes then apart from slipped timimg ( - unlikely - ) it is not the electrics/ignition.

If no, try for a spark at the king lead,

If yes the the rotor arm is tracking - clean and refit, if still no joy - replace it.

Or the dizzy cap is tracking - clean the inside, inspect and refit - if still no joy replace it

If no put another king lead or spark plug lead in the coil.

If you get sparks the orig king lead is faulty - replace it.

If no then it may be the coil.

Check the coil by touching an earth wire to the coil negative (that emulates the amplifier switching on the coil) to se if a spark jumps at the king lead, if no the coil is knacked - replace it.

If yes then possibly the amplifier or the hall effect pickup in the dissy are faulty.

The two things work together and both can be tested but its complicated so perhaps better to substitute them in turn to see if they are faulty.

It's more likely the amplifier, so check that first.

I think I've got the sequence right, - If I haven't someone will be along to put me right.

If all this is beyond you go to yellow pages and ask an auto electrician to test everything.

If it is not the ignition then onto fuel supply etc - a whole new ballgame - I assume its carbs - If so, I know nothing!

Thanks Ramon.
I have printed your instructions and will go have another look at the beast. For info, it is EFI, not carbs. I will let you know how things turn out.

Regards,
Paul

Paul, I missed some pretty basic things like checking all your earth connections/straps are clean and bright, and the obvious EFi checklist of ensuring all your ignition and efi wiring/connections are in good nick. Check my website for wiring/connector help - if needed.
Ramon