No spark, no start

[tom1985]

Afternoon all,

My 1000 conked out whilst out and about yesterday (after about 30 miles, up until which it had been running fine). Engine starting missing and then stopped altogether, and hasn't started since.

I've checked the fuel situation - I'm not sure what condition the fuel pump is in, but, to be sure, I took the top off the float chamber and filled that with petrol - and still nothing. The spark plugs have fuel on them so presumably fuel is getting to them. So with my (admittedly limited) knowledge I assume it must be something to do with the ignition system?

I've spent today trying to sort it out, and so far I've replaced the contact breaker points and condenser with new, and made sure the gap is correct with a feeler gauge (0.015). I have also tried swapping the distributor cap and rotor arm (with old ones that were working when removed from the car a couple of years ago and kept as spares), but none of this has made any difference. Based on advice on other posts here, I checked whether I could get a spark at either the king lead (by removing at the dizzy end) or the individual spark plugs, and cannot get a spark anywhere.

I've not yet tried replacing the coil, HT leads or anything else as I don't have spare ones yet.

Power is reaching the coil - multimetre reads 12V at the coil terminals. I have noticed that the coil isn't heating up at all when the ignition is switched on, which it normally would - does this mean the coil might have failed?

Any ideas on what else I could try to get it going? Thanks for your help!

[chesney]

Did you try and get a spark at the coil king lead while tuning the engine over?
Could be poor connections/wiring at the low tension terminals/lead.

[tom1985]

Hi Chesney, yes, I tried this by removing the lead from the coil to the distributor (at the dizzy end) and tried to get a spark by placing it near to the engine block and then cranking the engine round with the handle with the ignition turned on, but could not get a spark.

The coil does seem to have power going to it, registered by testing across it's 2 small terminals with a multimeter

[mogbob]

On the coil if you are getting : -
12 volts on the wire (In ) from the SW (ignition switch )
and 12 volts on the wire out CB ( contact breaker /points )
and the lucar terminals are bright and clean
and the female ends to the wires grip tightly
and with ignition on, engine cranking over, King lead from distributor cap held with insulated pliers held against a clean
surface on the engine block doesn't produce a spark then the coil is duff.

Oops, just had another thought / if ....to add to the list...is the low tension lead inside the distributor " sound " and ditto the earth tag at the points.They are not the most robust, if no electrical contact, no circuit and ultimately , no spark and no go !!

Bob

[bmcecosse]

If there is 12 volts at both coil terminals (measured to ground - you don't measure 'volts' across the terminals.....) - the low tension is FINE!!! I suppose the HT side could have failed.... Remember - it's NEVER the coil....(unless it's a new one ??) . To check further (since you have a multimeter) remove the wires and check the impedance across the two terminals ... should be 3.2/3.4 ohms. The internal 'low tension' wire Bob mentions is well worth checking. This is when a complete spare dizzy (and coil...) are worth their weight in gold !

[simmitc]

You can simulate the operation of the points: Remove the low tension connection on the coil that goes to the distributor. Ensure that you have the 12 volt supply to the coil on the other terminal, and prepare the king lead HT to the block as previously. Now use a spare piece of wire to from the disconnected coil terminal to earth. Alternately making and breaking the circuit by toughing the wire to earth will do exactly what the points do, but without having to crank the engine, and will bypass points, condenser, etc. May show nothing new, but can also help isolate where the problem lies.

[tom1985]

Cheers for your help guys - I'll let you know how I get on!

[katy]

I've replaced the contact breaker points and condenser with new, and made sure the gap is correct with a feeler gauge (0.015).

You may have contaminated contact surfaces on the points. Sometimes new points have an oil film on them and sometimes the feeler gauges have an oil film on them that can contaminate the points.

W/the ignition off and the points in the closed position, gently pry them open and insert a thin strip of clean (new) paper, let the points close, pull the paper along a bit to wipe the points, pull the paper until it exits the points. Look at the paper and see if there's any discolouration on it. Repeat if necessary until the paper comes out clean.

I've seen this happen numerous times so I always wipe new points after installing them, just to be on the safe side.

This doesn't work w/used points as they are rough and will snag the paper.

[mowogg]

Your initial failure symptoms do sounds like it could be a coil -i have had a few fail in identical circumstances. As suggested elsewhere this is typical of modern replacements. I would get another unit to swap in, and i would always carry a spare (unless you are lucky enough to have a serviceable old one fitted)

[bmcecosse]

It's NEVER the coil!!! Unless it's a 'new' one - very possibly wrongly specified.

[panky]

Co-incidentally I had the same thing happen to me last night As I had just fitted new HT leads they were the first thing to check but all was secure and nothing seemed amiss. I left the ignition on and was pushing the button on the starter every time I tried something, a couple of times it fired but died straight away, then I took the dizzy cap of to check for a spark, it was weak and intermittent. The problem turned out to be the nut holding the LT connections to the spring on the points had come loose (I wonder who didn't bend the tab washer back properly ) A quick tighten and all was well - worth checking.

[tom1985]

Just fitted a new coil. I then tested for a spark again by placing the dizzy end of the king lead close an earthing point - and got a spark. The plugs are sparking now as well. So, I thought - problem solved! Unfortunately it still won't start - any ideas what else I should check or try?

[bmcecosse]

It's NEVER the coil...check the connections...

[kennatt]

after changing the dizzy cap are the leads on the right order,easy to get them wrong.