Triumph Repair: Triumph Spitfire Ignition Systems, starter solenoid, rotor arm

Question
Jim, I have a Spitfire 1300 overdrive 1974. My problem started a few months ago with what initially seemed to be a flat battery which would not hold its charge. With a new battery a further problem developed. At over 3,500 rpm the engine lost power, seemingly from lack of ignition. Rotor arm and points were checked. Breakdown man suggested the alternator was not charging so it too was replaced. Same problem still. When using jump leads there is a occasional 'crack' from the bulkhead then no power at all. Is this the coil? Thanks


Answer
Richard,

I may need some more info before I can really get to the root of what you're dealing with, but let me try.

First off, I presume you're outside the US as you 1974 with 1300?  Correct?

On the bulkhead (firewall to us Yanks) are the battery, coil, and starter solenoid.  If you lose power completly then it's more likely a loose connection at the battery or solenoid.

As to losing power above 3500rpm, there are three ingredients to power in an engine.  Fuel, Fire, and Timing.

I'll run through them backwards in order of what I think you're dealing with.

Fuel:  

Make sure the dashpots on the carbs (should be twin SU HS2s) are filled with oil.  Engine oil, ATF, snake oil, whatever.  Guiness might even work, but I can't say that it won't dissolve the carb completely.

Check that all the linkages move smoothly.  A touch of light oil never hurts.

Have a friend sit in the drivers seat and push the gas pedal to the floor with the engine OFF... make sure the throttle butterflies open completely.


Fire:

If you have a spare sparkplug handy, pull one of the leads and put in the spare plug and wedge it somewhere handy, like at the firewall near the brake master (at least on LHD cars ;).  See if you have a vivid blue spark when the engine is cranked, or a feeble spark.

If it's feeble, make sure that the points are clean and gapped correctly.  Check all the connections on the coil (it wouldn't hurt to touch them up a bit with emery cloth).

Borrow a good voltmeter and check the plug wires (don't forget the high tension lead from the coil to the distributor) to see that they all have consistent resistences.

If it's still feeble it could be the coil

Timing:

Hopefully you have (or can borrow) a timing light to check the timing properly.  If so, start the car and check the timing.  You should see something like 6 degrees Before TDC.

If you don't have access to a timing light you can check the static timing.  

On point ignition systems you can disconnect the low tension lead from the distributor to the coil and substitute a lead with a lightbulb, connected at the other end to the positive post of the battery.    Set the crank pulley to 8deg BTDC and connect the light.  Loosen the distributor locking bolt and twist the distributor counter-clockwise slightly until the light just goes out.  Mark the distributor body where the #1 cylinder spark plug lead is on the distributor cap.

The rotor arm should be pointing basically towards the #2 cylinder.

I hope what I've detailed here is clear.


Cheers,

Jim