No Spark

[Morris57]

Hi Can anyone help please,

Started my friends Morris minor today,started fine then started mis-firing badly and then stopped.Tried to re-start it but nothing, car turning over but will not fire.Checked the plugs and no spark at all,removed the HT lead from the coil to dizzy and earthed it and there was a spark.Re-connected to the dizzy and no spark at the plugs.

Does anyone have any ideas what it may be please.

Craig

[bmcecosse]

Rotor arm or dizzy cap failed!

[Morris57]

Checked the rotor arm,cleaned it and also checked the dizzy cap contacts and cleaned them but not difference.

If there is a spark at the end of the HT lead from the coil does that mean that the condenser and the points are fine?

The carbon brush in the dizzy cap seems OK.

Would a crack or damage to the dizzy cap short the spark to earth.

Will changing the points and condenser not make any difference?

Sorry to be a pain but really need to get it running for Monday if possible.

Thanks
Craig

[RobMoore]

cleaning the dizzy and rota is not enough to rule them out as being the fault, since your getting spark at HT then the next logical step would be to test with another rota arm and then another dizzy. If this still does not sort, then look at condensor and points.

[autolycus]

A quick check if you have neither a known-good rotor arm nor distributor cap to try:

Take the distributor cap off and wedge it upside down on a rag. Put a suitable-size coin* inside the cap, resting on the carbon and one of the cap contacts. This replicates the effect of the rotor arm. Disconnect the plug lead that the coin is "pointing to", and either hold it near the block or stick a sparking plug onto it, and rest that on the engine.

Spin the engine over (ignition on) and check for sparks.

If this results in a spark, but you don't get one when the cap and rotor arm are both back on, then it's the rotor arm at fault - probably shorting through the plastic to the distributor shaft.

If you don't get a spark, but can get one from the end of the coil to distributor HT lead (the "king lead"), then it's the distributor cap that's shorting to the distributor body.

* An old penny or half-crown if you're a stickler for originality.

Kevin

[bmcecosse]

Good grief - even with my great age, I've never heard of this one!

[Morris57]

Hi Guys

Thanks very much,really helpful as usual I will try the coin in the dizzy suggestion great idea.

Thanks

Craig

[mike.perry]

Will a 1938 George VI penny do or will a 1963 Elisabeth II half crown have better conductivity?

[Morris57]

Shes alive!!

Thanks to everyone for their help,I decided to bite the bullet and replace most of the ignition system with new parts.

Condenser,points,rotor arm dizzy cap and leads,and new plugs.

This Morris has been off the road since 1989 so I thought it might be a good idea to replace the parts.

Anyway after selling PSL 184 and working on this Morris Minor that belongs to a friend,he decided he wanted to sell it,so I have bought it off him and now its my daily driver.


Its a 2 Door 1969 in trafalger blue,I have used it for the last 2 weeks and its been most enjoyable just a few small jobs to do on it but I am really enjoying driving it.My first car was a 1967 2 Door in trafalgar blue when I was 17 and I pasted my driving test in it.

Anyway thanks again for the help I am sure I will need so more guidance in the future,in the meantime driving with a big grin on my face.

[unclemarj]

hello, i wonder if anybody can help me with this one my old minor was running but it was lumpy
i got some advice to fit new condencer and points, having done that it will not give a spark over the points
it has been a few years since i was playing around with this kind of thing and i wonder if there is any advice you can
give me please...... h...e...l...p

[MarkyB]

Try drawing a piece of card between the points.
The contacts are often coated in oil to protect them while in storage.

The wires that go to the moving point need to be isolated from the post with a nut on the top.

[bmcecosse]

Refit the old points! You have obviously created a 'short' when fitting the new ones. I assume you have 'gapped' them ok ?