The Triumph Dolomite Club - Discussion Forum

Hello All

I am looking for some advice / guidance. The car has been out and about a few time these last few weeks without problem. It started well enough today and was sat idling whilst I closed the gates. Got back in and the engine died.

I have put 5L of fuel into the tank and I can see fuel in the 'in line' filter so I am guessing that it is not out of fuel.

I had my other half turn the engine over whilst I removed one of the HT leads - no sign of any sparks.

The Haynes Manual suggests that if the engine cuts out whilst running it it likely to be a Low Tension problem.

Any ideas as to where to go from there - and if it is the coil - are there any replacements around?

As I said at the beginning - some guidance would be useful.

Regards

Ray

SAB 243L

Have you checked for a spark on the king lead (the one from the coil to the dizzy)? If you're getting a spark then the rotor arm is a prime suspect. Try a known working one. Are you running on points? If you have electronic ignition then that could've failed.

Thanks - something else to try. Yes running on points still.

Regards

Ray

Toledo Man wrote:Have you checked for a spark on the king lead (the one from the coil to the dizzy)? If you're getting a spark then the rotor arm is a prime suspect. Try a known working one. Are you running on points? If you have electronic ignition then that could've failed.

A further update. The car started lfirst time after a cold night. However after idling for five or ten minutes it died again and refuses to start.

I was advised to check the SU float chamber - it was full of petrol and the needle valve seemed to be free.

Back to the electrics - I pulled out the king lead from the coil - no spark anywhere. Digging around I see the coil is a marked as Unipart GCL 111 (12volt) . The manual lists it as 15C6 or 16C6 which are 6volt coils. There is a newish looking ballast resistor (seemingly connected) bolted on the wing. Should the coil be 6 or 12 volt?

Thanks again

Ray

It certainly sounds like the coil is overheating and failing. If the car is fitted with a ballast resistor, you MUST use a 6v coil on it!

Steve

But it runs when cold.....
I would suspect the rotor arm. Try checking the king HT lead (ie where it plugs into the centre of the cap) to see if you have a spark there. If yes, but not at the plugs, it is the rotor arm or cap. If no spark, coil/points/condensor?

If you have spark from the king lead try this: removed dizzy cap and aim the king lead at the centre of the rotor arm but not touching. Get someone to crank the engine. IF the spark jumps to the rotor arm the rotor is cracked somehwere or very dirty with carbon dust causing the spark to earth out. If no spark jumps to the rotor I would change the coil.

Tony

Check the dizzy cap as well. I forgot to mention it. Ignition is definitely your first port of call.

Thanks for all the advice. The car is up and running thanks to a little help from a local mechanic.

New points, new condenser and a new rotor arm and the car pretty well started on the turn of the key. We tried a new coil but it was not needed.

The car is fitted with a ballast resistor and the manual shows a 6 volt coil. The existing coil which has the look of being very old is a Unipart GCL111 and is stamped 12 volts. I tried to persuade my friendly garage man that we should be fitting a 6 volt coil but he wouldn't have it. (He has an old Mini which he wins prizes with at shows - so he has some experience.) The car is obviously running with a 12 volt coil but perhaps that is the reason the points are showing signs of overheating? Perhaps Carledo / Steve could provide more details.

Speak again

Ray

Postscript

You can understand how the motor industry might not be able to measure emissions correctly when you see the way it labels components, for example this coil.



This is a six volt coil for use on a car with a 12 volt circuit fitted with a ballast resistor. Contrast the labels on the packaging with the information printed on the coil. Yes it is the correct coil for the packaging - you can read 'DG-COL202' on the end flap of the box which is the same as the stamp on the base of the coil.

The Manual for the Triumph 1500 FWD details a Lucas 16C6 - the C6 denotes a 6 volt coil. Currently the car is fitted with a Unipart GLC111 12V (the plastic cap is also stamped 12V just as the new coil pictured above). A Google Search for GLC111 brings up matches such as GCL132 which is on the labels of the new box shown above. The Triumph 1500FWD Manual details a ballast resistor - and there is one fitted on the wheel arch and attached to the wiring loom. (I just feel sorry for all the Triumph GT6 and MGB owners where the ballast resistor has been replaced by a factory fitted ballast wire - how do check that is still present?)

A search of various motor car forums produced this explanation:

Why a 6 volt coil in a 12 volt car?
With the points closed, current will flow as follows: battery to ign switch to ballast resistor to coil to points and finally to ground.
With an assumed charging voltage of 14 volts at the battery, we can measure voltage drops of about 8 volts across the ballast and 6 volts across the coil. THIS MAKES THE COIL OPERATE ON 6 VOLTS WHICH INDICATES THAT IT IS A SIX-VOLT COIL.


I am feeling much happier. The car is running and I am confident that the coil that is fitted (whilst marked 12V for use on a car with a 12V battery) is a 6 volt coil - just as detailed in the Manual.

No wonder people get confused and have difficulty explaining.

Hope this helps somebody else.

Good old British Leyland - or was it BMC as there are lots of confused MG owners out there as well.

Regards

Ray