No spark at plugs?!

Rhys25 · Apr 23, 2017

Hi,

I am putting my 2.25 engine back in after a rebuild and i have no spark at the plugs, before the engine seized it was running. I have checked for a spark at the coil by putting a spark plug in the HT lead coming from the coil and earthing it in the engine bay and there is a spark. I have fitted an accuspark electronic ignition module, I have cleaned the contacts within the dizzy cap but when i put a spark plug in the individual ht leads and earth within the engine bay there is no spark, the low tension side of the circuit has 12v and the HT side seems good to the dizzy cap, it is from here that the spark appears to fail. I have added an extra earth strap to the engine just in case it was poorly earthed but that doesn't seem to have made a difference. Any ideas?

Dippypud · Apr 23, 2017

Have you checked the dizzy cap ?

Rhys25 · Apr 23, 2017

Dippypud said:
Have you checked the dizzy cap ?

Ye, it all seems pretty good, I have cleaned all of the contacts in the cap both inside and out, no cracks in it

Dippypud · Apr 23, 2017

Rhys25 said:
Ye, it all seems pretty good, I have cleaned all of the contacts in the cap both inside and out, no cracks in it

Centre carbon still there ?

Rhys25 · Apr 23, 2017

Yep still in place, its got me scratching my head like a good un!

Dippypud · Apr 23, 2017

Rhys25 said:
Yep still in place, its got me scratching my head like a good un!

Check continuity between coil and cap see if rotor arm is short ...

Rhys25 · Apr 23, 2017

Dippypud said:
Check continuity between coil and cap see if rotor arm is short ...

Thanks for the suggestion Dippypud, I will give it a go

John S · Apr 24, 2017

Is the module wired in correctly, something is earthing?

fv1620 · Apr 24, 2017

The gap on a spark plug is quite narrow & not a reliable test that you have enough HT. It would be better to take the king lead from the coil & hold the end of it 5mm from an earthing point. I can get a spark of 10mm but less than 5mm you have low HT.
You need to test the rotor arm, you cannot do this with a multimeter, you need to test it at the voltage it will be running at. Again with your lead from the coil HT hold the end of it 2mm from the metal of the rotor arm whilst is still on the distributor shaft. You should get no sparking at all.
You say the carbon brush is still in the cap, but is it free to move on its spring?

Colthebrummie · Apr 24, 2017

I think if I had gone to the trouble of rebuilding an engine, I would have replaced the leads, dizzy cap and rota arm at the least.
Col

Rhys25 · Apr 24, 2017

Cheers for all of the suggestions, it is now working brilliantly, the culprit was the carbon brush sticking in place.

Rhys25 · Apr 24, 2017

Colthebrummie said:
I think if I had gone to the trouble of rebuilding an engine, I would have replaced the leads, dizzy cap and rota arm at the least.
Col

Leads were new 18 months back, rotor and dizzy cap performed fine before rebuild, i get what you are saying but in my opinion if it ain't broke don't fix it!

No spark at plugs?!

Rhys25

Member

Dippypud

Never Knowingly Understood

Rhys25

Member

Dippypud

Never Knowingly Understood

Rhys25

Member

Dippypud

Never Knowingly Understood

Rhys25

Member

John S

Well-Known Member

fv1620

Active Member

Colthebrummie

Well-Known Member

Rhys25

Member

Rhys25

Member

Similar threads