Triumph Repair: TR6 will not start, fuse block, cap center

Question
I have a 76 TR6 that I was driving around recently.  The car was running fine when the engine suddenly died and would not re-start.  It was acting like a fuel supply problem but I have ruled this out.  After closer examination, I found that I was not getting any spark when turning the engine over.  It looks loke it may be an electrical problem.  What would cause the car to die so suddenly? Coil, points, etc.?  I live in CT. Thanks! Chris Terry

Answer
Chris,

If any of the electrical connections came loose then the car will die suddenly.  I seem to recall that one of the critical ignition wires does something intelligent like loop around the steering column shaft.... I found that out the hard way in my '73 Spitfire (same steering column as the TR6).

Start with the easiest things.  Disconnect the + coil lead (should be a white wire, the white/black wire should go straight to the distributor) and turn the ignition on.  You should have something resembling 6 to 12 volts.  

If there is no voltage at the coil then you need to start a power hunt.  The power for the coil comes off the ignition switch as a white wire and continues to the fuse block (but doesn't appear to be fused.. typical) and continues on to the coil as a white wire.  

The wiper motor is on the fused side of that connection, so if the wipers don't work then check the appropriate fuse.  Another possibility is that the ignition switch (electrical switch part) had finally given up.  One word of caution, that switch is held to the lock mechanism by two tiny screws that must be removed first.  If you just tug on the wires, the switch has a tendency to distintegrate. Ask me how I know.  :D

If there is voltage at the coil, turn the ignition off, reconnect the lead to the coil, and remove the high tension coil lead from the distributor cap center.  Wedge the wire somewhere along the engine where the metal end is close (1/8" or so) but not touching a grounded piece of the car.  The area around the valve cover where the head studs are visible is good place to try.  

Have a friend (neighbor, wife, etc) turn the ignition on and crank the engine while you watch the end of the high tension lead.  If there is no spark then it's most likely the points.  If there's spark there... then it's onto the distributor itself.

Look inside of the cap and make sure that the rotor arm contact is touching the carbon contact in the distributor cap.  Check the condition the inside of the cap and clean it out if necessary.  If there's excessive carbon buildup on the inside of the cap it can short out the ignition leads.

If you have spark but the car still does not run, check the ignition timing.  One problem I experienced (with that same Spitfire) is that the advance counterweights became gummed up with 15 years of oil and grime and would stick in place at full advance.   Above 2000 rpm that's ok, but the car won't idle.

Hopefully I've given you a good starting point for figuring this out.  


Cheers,

Jim