No (accu) spark - test sequence?

[JonE]

Just going through a diagnosis for a no spark after no physical changes other than pushing a bit of wiring up out of the way of my pedals/feet. Went into garage perfect and now on wanting to test tracking improvements, nada.

I've got no functioning standard distributor to swap back over, and just want to find out what could be down the accuspark unit (which was operating very very well) and what down to something else...

1. No spark from end of lead on firing the starter
2. No spark from the HT centre lead from coil, when firing the starter
3. Swapped coil for new one and no difference so I've put it back onto the old one.
4. Gone over the back of SM5 and all wires are in place and done up.
5. I've checked that the across the posts ohmeter reading on the coil is above 1.4 (on both it was about 1.9)


I'm presuming nothing to do with control unit as that is only charging. Not sure whether point 2. can discount the distributor being a problem or not.

Next procedure?!

[AustinWood]

Have you checked whether there is voltage at the coil when the ignition is on?

[Austin Carr]

Where does the piece wire go that you moved? If it is part of the ignition, moving it could have caused a poor connection at one end or there could even be a break in the wire.

[JonE]

THanks both. Slight progress. Jim - yes, 6V to coil. I did go over the wiring again.
I've just found an old DJ body, swapped it over using the Accuspark cap and..... it started!

I see from their website that copper leads can cause interference. Could that mean it could kill the unit? I didn't know that when I bought it.

Just looked and its out of warranty. 3 miles use as its been in a box new.... I wonder if its possible to retrofit an Austin baseplate and get some decent use out of it?

[Alastair]

Jon - I've been using copper leads ever since I bought mine about two years ago and have had no problems... touch wood!
Alastair

[Ruairidh Dunford]

I have used copper leads exclusively, without any issues.

Phone them, explain the situation and I am sure they will be reasonable.

Any loose connections on these units will kill them - it is also worth noting that they will not operate if your battery falls below 6v.

[andrew34ruby]

..... - it is also worth noting that they will not operate if your battery falls below 6v.

I would expect many 6 volt batteries to drop below 6 volt while cranking the starter motor. Is it a case of 'if it doesn't start first time it'll never go'?

[Ruairidh Dunford]

My own solution, if the battery is soft (usually when it is very cold), is to flick the starting handle over.

[Andy Bennett]

Sounds a little similar to my failure of my Accuspark unit, described here:
http://www.austinsevenfriends.co.uk/foru...7#pid22567

Mine was down to the weights having failed on their pivot peg so the rotor was slopping back and forward over the advance and retard

They were very reasonable and replaced the out of warranty unit.

Andy

[JonE]

All very interesting re: voltage, thanks. I can see that last night if I'd had the battery on 6.3 it might not have started if I'd have been lazy and used the starter.

Fortunately, I'd had the battery on smart charge overnight and it was at 6.7 (fixed, Lidl!) in the morning before behaving the same. I've emailed them saying please could I perhaps pay trade for the new electronic bit, IF they feel they cannot replace it in the circumstances.
I'd like a spare trigger unit in the car if I'm using the Accuspark (but am now working on my DK4A which makes sense to have going)

Re. loose connections on the unit, how far does that extend into the wider car wiring? Two nut/stud connections on a coil are pretty obvious to make sure are fine. Are HT leads contributive? other wiring feeding the coil? I don't think that was the case with mine, but it's good to understand these things.