Getting to the bottom of the Spitfire’s ignition quirks

Haynes' World is a regular feature that takes a look at what the staff at Haynes are doing with their cars, bikes and other vehicles. This time, product manager Nigel Donnelly reveals how he's getting on with his Triumph Spitfire Mk4.

In the TV episode, Gus and Will discuss that the car has electronic ignition when investigating some running issues. Not any longer it doesn’t. 

In fact, there is a shiny new distributor on the car and traditional points ignition. I suspect what has happened is that the car wasn’t running correctly and a bit of part swapping has taken place to fix it.

It is tempting to blame old electronic ignition systems because you can’t easily test them as you can with points, so it has been reverted. A new distributor, points and rotor arm are also in evidence, but it has not been ‘put back’ to original so much as ‘got going’. There are a few things that suggest this.

The first issue is that the distributor is not the correct one for the car. The clue to this is a cable dangling under the bonnet for the mechanical rev counter. The new distributor fits and functions to allow the car to run sweetly, but the correct ‘Delco’ one is taller and has the mechanical drive for the rev counter.

New parts on order for the Spitfire

I hadn’t even noticed that the rev counter doesn't work but at least I know why. Hopefully getting the correct distributor will fix that. I have also noticed that the HT leads are not a matching set. That does not scream ‘good maintenance’ so a new set of those and a nice new set of spark plugs feel like a good investment.

In order to get the car off my friend's driveway, there had to be a certain amount of ‘mucking about’ to get it running. He said that he had run a temporary feed from the battery directly to the coil to get it to start. Alarm bells! This also means that, once started, it won’t turn off with the key. You need to clamber under the bonnet and remove the feed. This is top of the list of things to investigate.

I suspect either some sort of issue with the ignition switch or more likely, more issues with the recent ignition electric work. I've been printing out wiring diagrams from the Digital version of the Haynes Manual for the Spitfire to help work out what the original set-up would have been and whether the current set-up needs further attention. Given the mixture of bits fitted, I wonder if it might have the incorrect coil fitted? A bit of detective work with the multimeter is definitely on the horizon.

Anyway, the little four-cylinder Triumph engine is very simple but it was running horribly when I went to collect it.

It started well enough on choke, but proceeded to run more and more poorly until it simply gave up, cut out and refused to start again. A quick check over and my eagle-eyed pal spotted the choke cable was moving but the choke actuator on the twin SU carbs was not. It had stuck open.

Lubrication saves the day

A firm prod restored function and a little smear of light oil prevented recurrence. The recent refurbishment had left the carbs sparkly clean and but also dry. Most British sports cars of the era provide a film of oil over the entire engine bay just because they do. The Triumph had been standing for a while and, as we all know, cars do not like not being used. A little seizing up is to be expected. 

Once running, it actually made its way happily along a mix of motorway, A- and B-roads, and improved with each mile as it loosened up and blew a few cobwebs away.

A friend following me noticed a very dim brake light too, which should be an easy fix, but again indicates that the multimeter might be getting a workout at both ends of the car before she sees the road again.