No spark (resolved)

[kevtherev]

No spark
Ok so I was doing some maintenance on my carburettor.
Started and ran stopped to adjust tickover three times.
Realised I had left the vac lines off doh!
Reattached and nothing.
No spark from the coil
Checked coil resistance OK in spec for resistance
Changed amplifier for known good
No spark
Changed distributor for known good
No spark
Checked all connections for continuity OK
Checked all wiring between the components for continuity OK
Ensured good engine earth
I have 12.6 v at the coil ignition on (green lead)

Stumped

[kevtherev]

How do you check the distributor pick up unit?

Ive ordered a new ignition amp.

[bigherb]

I've written this so many times you must have missed it when you did a search.

Remove the centre HT lead from the distributor and hold it about 5mm away from a metal part of the engine or bodywork and away from the fuel system.
Remove the three pin plug from the distributor and probe a piece of wire into the centre pin of the plug.
Switch on the ignition and then scrape the other end of the wire along a metal part of the engine this should then produce sparks from the HT lead.
If you get sparks then the rest of the ignition system is OK and the hall sensor is at fault. If you don't get sparks some other part of the ignition system is at fault.
Before you replace the sensor check there is more than 5 volt across the two outside pins of the three pin plug.

[kevtherev]

Ok thanks pal.
Ill report back tomorrow.

Never thought this would ever stump me, as I have all the parts.
It was so sudden and permanent

[kevtherev]

Ok so there's no spark from the lead when I tested it
There's no voltage between 1 & 3 either.

Showing 12.7v at the coil voltage and at the live stud in the junction box.

Coil tests at 0.8 ohm primary
7.4 ohm secondary

[937carrera]

Just a quick response for you Kev until Bigherb turns up.

Have you checked all 7 connections to the ignition amplifier - page 3 of the DG wiring diagram pdf ?

(grey coil I assume)

[kevtherev]

Just a quick response for you Kev until Bigherb turns up.

Have you checked all 7 connections to the ignition amplifier - page 3 of the DG wiring diagram pdf ?

(grey coil I assume)

Checked as in how pal?


Redid the coil earths.
Made a new king lead up
No spark

[937carrera]

Check all the physical connections are in place, voltage where there should be, no broken wires, continuity from each wire to the connector block.

With it being so sudden it's quite likely that it is something you have (unwittingly) done

http://syncrosport.com/info/wiring/

From what you have described I agree the issue seems to be in the ignition amp area

[kevtherev]

Just a quick response for you Kev until Bigherb turns up.

Have you checked all 7 connections to the ignition amplifier - page 3 of the DG wiring diagram pdf ?

(grey coil I assume)

In a round about way you got me in the right place.
I checked all the wires to the amplifier and had 1 brown left over.
Tracing it to an eye connector on the engine under another loom.. it crumbled in my hand.
All good now, fired up straight away.

Thanks to Big herb it narrowed the field down to the circuitry
So cheers pal for the test procedures.

[937carrera]

The absence of the 5v across the pins gave a very strong pointer as to what was wrong.

The fact that all was well until you started messing was the other. As a tech I know says "if it was working before and it isn't now, then it's something you have done, check your work !"

The brown wire was the earth then, you probably just disturbed it breaking the earth route. Aren't you glad it happened while you were at home

[kevtherev]

The absence of the 5v across the pins gave a very strong pointer as to what was wrong.

The fact that all was well until you started messing was the other. As a tech I know says "if it was working before and it isn't now, then it's something you have done, check your work !"

The brown wire was the earth then, you probably just disturbed it breaking the earth route. Aren't you glad it happened while you were at home

Where the earth point is, was no where near I was working.
I think this was just coincidence, and it decided now is the time.
A hidden earth point is easily overlooked.

Oh boy am I glad though you're right!
We're off to Spain in a few weeks...the mind boggles

[Cobra88]

Glad you found the cause Kev