spark of life?

[mettersl]

Hi John
It was about 6.5 to 7v depending on the earth I managed to get (when the engine isn't cranking). If anything this seems a little high.
Doing the maths- it should be a little under 50% of battery voltage as it looks like the ballast resistors are both the same value. Battery was down to 11v.
I have just scanned the relevant pages of the manual and there is a diagnostic check on this area- involves a magnet and an old TDC sensor. Fun for Saturday....

Lee

I have just scanned the relevant pages of the manual and there is a diagnostic check on this area- involves a magnet and an old TDC sensor. Fun for Saturday....
Lee

Hi Lee,
It does look as though this voltage could be ok, pity I didnt do that check before. It would be interesting to see what voltage is on your 610, I suspect it has the same type of ign system, but I could be wrong.
Yes I have that info re the check for a spark with the magnet, and TDC sensor. But I hesitated about posting it, as it gets a bit tricky, However................if you feel confident, the one on the atmo is only used for diagnostic purposes, so you could whip it off and do the check with it. if you have a magnet But we are moving into quite deep stuff here. So go for the leads, like the other guys said, and see what happens.
PS, it is possible that this 4v to 6v could move around a bit depending on where the distributor stops, in relation to the pickup coil, as this could reflect back to the ign unit. These Black Box units are very annoying, you can never find out exactly what is going on inside. Bring back the old points and capicator system I say, you could always get yourself home with those, with a bit of ingenuity.
Good luck
Now I really must go and do that packing
John

The Atmo and turbo engines have a completely different ignition system.

FWIW though, a standard DeLorean system (same as an Atmo) has no trouble maintaining the spark in a turbo engine!

The Atmo and turbo engines have a completely different ignition system.

Hi Martin, Thanks for that information, I am sure Lee will pick this up.
Cheers John.

[mettersl]

A610 and Turbo are the very similar but completely different to the Atmo....but I didn't know the Atmo had a (unused) TDC sensor- I saw the diagnostic plug and assumed that was just for starting remotely.
Well it "something for the weekend sir" now
Lee

[mettersl]

Well another backbreaking day and still no spark (aside of the occasional one when the ignition is first turned on). We are running out of components that could be faulty......
What is definitively OK.
Ballast resistors, coil, HT leads, dist cap, rotor arm, supply to coil, all connectors. The Rev counter is still not twitching, but is also not shorted or pulling things high, all connections work, the coil in distributor looks to be ok- 600 ohm resistance, gives a signal when a magnet passed over it (at the dist and at the ignition unit) - but still no spark at HT leads. The Immobiliser is NOT the problem. All connections to ignition module OK too- checked signals and continuity.
Conclusion- ignition module has given up (most likely) or the dist. coil is actually faulty (less likely as it looks to be OK electrically).
Martin has offered to provide an ignition unit to check...so we'll find out if there is anything else that could go wrong!
Its depressing NOT finding a fault, when it still not working, but I do have a nice shiny bruise on my forehead from the hatch...

Oh well..

Lee

I think I have a whole atmo ignition unit and coil he can have free of charge if he wants it.

[stephendell]

Have you tried running a direct 12V supply to the coil.

(It's a good get you home fix for the atmo, but don't leave it on permanantly or the coil will melt!)

If the car now runs then the fault is with the yellow wire to the multi plug at the bottom of the igntiton module.

[mettersl]

Hi Stephen,
There is already 12v to the coil unless the other side is connected (bringing in the ballast resistors) which beings it down to 4-6v. The last connector has already been bypassed so sadly in this case I don't think this fix will work.
David- I'm sure that John would be very grateful for the parts.

thanks everyone

Lee

[stephendell]

There is already 12v to the coil

Via a direct lead from the battery junction box on the firewall?

Might be worth a quick check.

Take distributor cap off, and turn over the engine, assume that the distributor arm is moving

[stephendell]

The 2 pin plug from the distributor can also be suspect as I think someone has already mentioned. The wires go very crispy!

I had one atmo that I spent a whole day tracing faults on with no spark. Although the 2 pin plug looked like it had been connected fully one of the pins had pushed slightly back out of the connector and that was the problem.

Other than that it's nearly always the 12V feed to the coil or the igntion amplifier itself.

[mettersl]

Hi Thanks everyone- I have checked all the connections to the distributor, main coil and the electronic ignition unit- all are fine. You get all the correct voltages at the main coil, and the coil in the distributor is giving pulses at the electronic ignition if you wiggle a magnet over it. The connector between the green distributor lead trigger coil and the loom is fine, the multi-plug connector beside the coil is has been partially bypassed (the 12v feed goes direct now). I am pretty sure that there is a fault in the electronic ignition OR the coil is giving too small a signal.
One fault I have not checked is that the distributor is turning. It is not free- (you cannot turn the rotor arm) and the engine sounds to have normal compression- this wouldn't be true if the camshaft was not turning would it?
I'm waiting to try another electronic module before looking into distributor or distributor drive issues.
Will be glad when we get this one running again....as will John!
Lee

Another silly that can be missed, and worth a look, in the centre of the disty cap (inside) there should be a sprung 'carbon' pin, is it still there and is it still 'sprung' ?

Hi everyone

Lee's been great on my sparky problem, he has shed blood ( fingers!) sweat ( even in the cold! ) and tears ( banged head!). All thats missing is joy ( when the beast wakes up! )............only when!!!!!!!!!.

Martin is sending me the bits ( cheers Martin ) and Lee is coming down for some more punishment ( cheers Lee ) we will take all advice given and act on this....thanks.

David thank you for your kind offer, i may take you up on it.

Fingers crossed John.