Forums Forums Enthusiast Forums A - Z Autowirral coil / condenser

I am like many am willing you to fix this

Turnips dad here - If the engine, when hot is still refusing or is reluctant to start these are the basic checks I would do when it is not starting.
Checking the ignition primary ignition circuit -
This model year is too early for a ballast resistor so I am assuming with confidence that it is a “standard” ignition setup, ie 12 volt.

Take a test lamp ( use a 21 watt bulb as this will give enough current demand and will be more susceptible to highlight high resistances) and place one wire to the positive on the coil and one to chassis ground, it should light once the ignition is switched on. Now leave the wire connected to the positive side of the coil in place and take the grounded wire and put it on the negative side of the coil, if you now rotate the engine the light should come on and go off as the points open and close, if the pulsing of the light is erratic then you have a continuity problem.

To check that you have HT voltage use your Xenon strobe on each HT lead including the King Lead, again look for erratic pulses. If you do have erratic pulses check the HT leads (they can become hygroscopic and susceptible to moisture contamination) also check the rotor and cap for tracking and arcing.

I know you have replaced the condenser but I have known them to fail quite quickly and I have had some which were faulty straight out of the packet and because of the nature of the failure (it was the wire connection to the foil) it was relevant to heat build up.

The HS4 is a simple and reliable carburettor and unless it is gummed up or there is no fuel delivery to the float chamber then it should operate. You mention that you weakened off the carb and it seemed to start better albeit with a few coughs and splutters. If you have a weak spark it is more likely to be quenched with a rich fuel/air ratio than a weaker ratio.

These engine do not like tight tappets, check the valve clearances, if my memory is correct they are inlet 0.010 and exhaust 0.012.

I relish a challenge, I would be happy to take a look. I am tied up over this weekend fitting a BMC 1500 diesel and rewiring the engine room on a canal boat but could possibly have some time mid-week or later.

If you do check the tappets use the rule of nine - ie, valve number one fully depressed adjust number eight, valve number five fully depressed adjust number four etc.

Just another thought, again if my memory serves me correctly (it was a few decades ago when I worked at Windsors) there were two different types of lucas condensers for the Austin/Morris/Rove etc range. one was an 18 microfarad and the other was a 22 microfarad, yours should be the 22 microfarad.

Lots of useful stuff there Turnip's dad. Many thanks. I will see how I get on. Progress may be a bit slow because yesterday I fell off my motorbike. Well, actually I was stationary and the bike fell over because I had parked on a slope, but I strained my back trying to stop it falling and then picking it up again. There was no damage to the bike but I feel a bit fragile so I need to take it easy for a day or so.

Snod

mechanical oil pump cog or spring loaded rod to cam. steal Rod was of a softer metal and was liable to wear.I think yours is a cog. Just a thought zzzzzzzzz

Temptation was too great - had a bit of a "fettle" on the engine this afternoon ie fiddled a bit more with the main jet adjustment.

Result? Pleased to report that the engine is running even better. After doing some 10 miles of so on top of the miles yesterday the plug electrodes are now a light chocolate colour as I remember they should be. Previously they were generally very sooty.

AND - AND - the hot engine is starting. I would not say perfectly ie still a bit of hesitation but I can live with that. Several times I have tried a restart 30 secs, 2 mins and 5 mins after stopping a hot engine -- and it has restarted.

What else have I done?
The things Turnip's dad suggested ( all the tests said OK)

AND I took the in-line fuel filter out. Why? Because the filter body DOES sometimes fill with vapour/ air or whatever especially after a run. This can easy fill half of the filter and it is quite a big filter. MY THEORY was that heat from the engine was affecting the fuel ie making it warm and to produce bubbles, and that when trying to restart the hot engine the fuel pump had first to displace this vapour or whatever through the float chamber before the engine would run. With no in-line filter there is only the very small volume of fuel in the thick walled rubber type pipe from the pump to the carb. MY logic was that the pump would very quickly displace any small amount of vapour from this pipe and that would not affect the float chamber enough to inhibit starting

Emphasise - MY THEORY. Could be total bull**** of course but maybe, just ,maybe it has helped.

The engine is now running so well and I believe it will hot start good enough that once a bit of corrosion on the underfloor has been repaired next week - I would have confidence to drive the car down to Bath. In Bath there is a guy who has "expressed a keen interest" in buying this Classic. He came to see it last week end but was a bit put off by the poor starting etc. I am trying to revitalise his interest.

Snod

Well done Snod,but I'm almost sorry you seem to have fixed the problem as I was enjoying following your trials and tribulations and all the suggested remedies.

Well done Snod; thank goodness for a car which isn't all black boxes when you open the bonnet and which you can actually fix with a hammer

Well done Snodvan I was enjoying your trials too.

I have a new condenser and a coil of a triumph spitfire both working when swapped for electronic. PM if you are interested. Also a new set of points if they are compatible, never used.