24 replies to this topic

[Lplus]

the spark was not from the HT wire; it was from the bodge wire to the head.

I orignally had nothing via the distributor; (I've even tried using different spark plugs to eradicate THAT possibility) that was my initial check when it broke down; i set a plug on the block and had no spark when i cranked it.

Today i thought I'd try and find out if it was the coil or the ignition, .....or the wiring.

On the basis that i get a spark from the dummy wire to the block; i MUST have a circuit, which thus means the wiring is ok (or is it?; anyone) however the lack of spark at the plug using either coil makes me think i'm missing a trick somehow???

 

I also checked the lead for continuity but as its a silicon lead I don't think that test works! (alternatively all my leads have failed simultaneously) I'm quite good at welding but have realised I'm rubbish with electrics!

Perhaps I misunderstand.  did you get a spark from the coil ht socket direct to the head?  If so do you still get a spark from the coil ht socket to the head if you fire the coil using the distributor instead of a piece of wire from positive.

Edited by Lplus, 11 August 2022 - 08:09 PM.

[brownspeed]

No; i put a plug in a HT lead; direct off the coil- by passing the dizzy. i turned on the ignition to liven up the coil with a dummy wire off the (-ive) coil terminal. i touched this to the block. there was no spark at the plug but there was a spark between the wire and the block

[Earwax]

I am sorry you are having a poor run, these can be irksome to say the least.  I have found for diagnostics I prefer to go back to a simple points and plain coil approach including leads- preferably off a known runner. In an ideal world it would be nice if you could just swap one piece out at a time - but often electronic dizzies need different coils.

 

I have also heard/seen , brand new electronics being DOA , or only lasting a short while - many times being put down to leaving ignition on for too long or misreading install instructions and fritzing the unit.  

 

I have had long lasting success with a Petronix system ( a couple of different matched versions) - but when it died it took me too long to diagnose it ( my fault)

 

I also have very good faith in the reconditioned points / condenser units sold by Distributor Dr - and come with 3 year warranty and he will build the timing advance  to suit your spec.

 

Best of luck . Cheers

[Lplus]

No; i put a plug in a HT lead; direct off the coil- by passing the dizzy. i turned on the ignition to liven up the coil with a dummy wire off the (-ive) coil terminal. i touched this to the block. there was no spark at the plug but there was a spark between the wire and the block

I just tried this with a known good coil, leads and plug and go no spark at the plug even though the dummy wire from coil neg to the engine sparked.  I think the coil needs a bit more than just an on off switch.  The condenser or whatever the electronic system uses for concentrating the power at the low tension circuit is needed to get the voltage for a spark in the HT side.  I don't think you test proves anything.

[brownspeed]

Ahh!! thanks! that IS useful info. I think i'll start by getting a new ignition pack and take it from there. very much appreciated!!

[Nial]

Don't forget the rotor in the distributor has to be pointing to the spark outlet you're connecting to when doing this, or you won't see anything (if I understand what you're doing).

[brownspeed]

Thanks Nial, but i effectively by-passed the dizzy (or tried to by taking the HT outlet from the coil direct to a single plug lead and plug) to try and ascertain if the problem was the coil or the ignition set. It seems I can't tell using this method, so I'll guess its the ignition and see if i'm proved wrong. will keep you all posted

[brownspeed]

Epilogue (for those who remember watching "the streets of San Fransisco").

I purchased a replacement electronic ignition unit (from a different manufacturer) which I duly fitted -resulting in no improvement. So it turned out to be the coil (the newest component on the vehicle) after all! I contacted Accuspark, who replaced it immediately with no quibble. fitted the new unit and she fired up and ran sweetly. also the misfire what I assumed was Ignition/mixture has vanished so suspect the coil had ben always faulty.

 

Incidentally Accuspark also advised that the resistance reading should be around 1.5 ohms when measuring across the terminals. I wish I'd asked them this at the outset! so now you all know

[Nial]

"Incidentally Accuspark also advised that the resistance reading should be around 1.5 ohms when measuring across the terminals"

 

Although this is dependent on whether you're running a ballast resistor (system?) or not.

 

I can't remember the details but if you check out AC Dodds tuning videos on youtube he discusses what's needed.

 

[brownspeed]

sorry; yes; mine is a ballasted system. 

I did not know the AC Dodds videos would've been help