TR6 Intermittant starting problems

[Marksg11dna]

I finally diagnosed and fixed for now a frustrating starting problem on my '76 TR6. Turned over nicely and there was a spark at the plugs and 5 volts at the coil + terminal. I rebuilt carbs, had the distributor rebuilt, timing, valves, etc where OK. FINALLY it came down to a faulty ballast wire. The wire was intermittently faulting therefor hard to diagnose. So, I replaced the ballast with a standard external ballast and the car started right up. But I was now getting 12 v to the coil. So I've bypassed the ballast all together with a wire joined at the ignition switch and changed to a non-ballast coil.

Two questions: 1) Will I need to go back to a ballast system when the weather cools (I won't run it in the winter in Chicago)? 2) There was a 2nd wire on the + side of the coil that was dragging down the voltage to about 2.5 volts. I clipped it and everything is still fine. What is that wire?
-Mark

 

[trrdster2000]

Mark, if you are going to get rid of the resistor then get rid of that coil and get a Lucas Sport Coil and you will make your TR6 a happy little motor car. You are not the first to have trouble with that system.

Wayne

 

[poolboy]

The 73 thru 76 cars had a ballast resistor wire conjoined to a white/yellow 12 volt starting wire that were connected to the positive side of the coil.
With points in the distributor, that's all that should have been connected to the + side of the coil, with the possible exception of a wire from a radio static suppressor, mounted near the coil
Do you see something that looks like a condenser, possibly blue in color, connected to that wire you cut ?

 

[Marksg11dna]

The 73 thru 76 cars had a ballast resistor wire conjoined to a white/yellow 12 volt starting wire that were connected to the positive side of the coil.
With points in the distributor, that's all that should have been connected to the + side of the coil, with the possible exception of a wire from a radio static suppressor, mounted near the coil
Do you see something that looks like a condenser, possibly blue in color, connected to that wire you cut ?

Thank you both for responding. I did indeed replace the original coild with a nice coil for a non-ballast system. Yes there were 2 wires on the positive side, both cut now and replaced by a wire I added straight from the ignition switch. Is the ballast wire the solid core wire? Interstingly the yellow/white wire was dragging the voltage at the junction to 2.5 v. I also removed the radio static suprssor "just in case". I'm installing a "Retro" digital radio so we'll see how that goes. The car runs great now. I've kept the 1.5 ohm coil and an external ballast on the shelf as a back up.

 

[TR3driver]

Interstingly the yellow/white wire was dragging the voltage at the junction to 2.5 v.

That might well have been the original problem. I had the same thing happen on a Stag, the white/yellow was broken at the starter solenoid and swinging around. In my case, it would touch ground when going up a slight hill, causing the motor to cut out. Then the deceleration would let the wire swing back and the motor would run again, causing the wire to short out, etc.