It's most probably one for Geo or Jasu, but if anyone else can offer advice, it would be very welcome.
It's regarding a points-assisted unit which a customer asked me to fit to their car, which I'd been preparing for an MOT test.

On setting off on the 25 kilometre mile drive to the test station, with this electronic unit operative, the car didn't run well, being down on power, juddering as it accelerated and struggling to reach 90 kph.
I stopped after about 5 km, swapped the ignition back to standard and the car then ran perfectly, getting to 110 kph easily...

Once back home, I checked the ignition advance with the unit active and disabled and found that somehow, it was managing to cancel out the centrifugal advance.
The only thing I can guess that could cause this is some fault in its circuitry which introduces a delay, even of a few milliseconds.
My question is, is that possible?

The vendor/manufacturer refuses to accept that the unit could be faulty.
Two videos, which I hope demonstrate the problem...
.
0797 is with the electronic mode switched off.
https://www.dropbox.com/s/w82x1j2f38sc3 ... 7.MP4?dl=0


0795 is with it on, in which mode the centrifugal advance is countered by the spark delay.
https://www.dropbox.com/s/xvqk1y0dlitjx ... 5.MP4?dl=0

Thanks in advance,
Ken

Does it require the advance weights to be removed?

Edit
I'm confused because I don't know why you would want to cancel the advance!

Roger,
no, the advance weights, points cam and points are retained, since it's just a simple amplifier, using the points as a trigger.
It has a switch to change between 'normal' operation and 'electronic' mode, however that change cannot be made with the engine running.
They don't spell out why that is, but it's a fair guess that damage would be caused to the device.

It's this POS...
https://blog.simonbbc.com/faq-helper-pa ... er-module/

Is the unit picking up interference from the plug leads ?

Can't help with any analysis, but I did have an eighties Charleston for a while with an electronic Lumenition assisted set. Running it with it on, and with it off, made absolutely no difference to performance or fuel consumption, though the points did last longer when switched on.

As suggested already, it could be interference. If it consistently works without the unit, that rules out the advance weights.

Poor connection do odd things.

The only other common component to both systems, is the condenser.

1./ Condenser.- Check with a capacitance meter.
2./ Dwel angle. - Check with a automotive multimeter.
3./ Points leaf spring.- Try a new one.
4./ Little screw earthing the condenser base to the points box.- Check resistance with a automotive multimeter.

My money would be on a faulty unit, particularily reading that it varies the dwell angle. Varying the dwell angle will vary the timing unless it's clever enough to switch off the coil charging before the points open but delay triggering until the points opening time.
Can't you insist it's faulty and get them to test it or replace it as a test.

Is that box mentioned to have the original condenser with, or removed? Some contact breaker controlled amplifiers need to have the condenser removed, to have proper way to work...

If tha t box is only for make the points last longer, then it should not to alter the advance at all, and that's the way I suppose that should do. Go to the seller, and show the behavior, and see what they say. The behavior what you wrote, doesn't seem how it should work...

A "fault"causing this delay I don't believe. You need to calculate the exact timing to eleminate the points advance like it does in the video..

The only thing I can think of is the capacitor losing it's stored energie and then trigering the spark with a delay. So as Jasu said: disengage the capacitor and see how it goes then..

p.s. every electronic ignition (including mine) is exactly doing what you discribe here..... introducing a delay to make the spark happening at the exact calculated time..

p.s. 2 I have never have seen the bennefit of these point assisted luminisuish spark amplefiers.. It is not so much work to set up points every 10000 miles or so..


ok. ok. now I'm throwing in my own windows (Dutch saying), but I'm doing it for better performance, better economics, never need to adjust it aso.. BTW. you can't run a compressor or turbo on points pfff..