Luminition optical trigger

[vxah]

I’ve been having major misfire issues with the TC that uses an optical trigger to run an Aldon Amethyst mapped advance system. It seemed at first to be caused by the new plug leads I had fitted as fitting a 30 year old set seemed to cure the problem. However, lots more time spent testing and another set of leads ends up pointing at the optical trigger as the culprit.
I thought this sort of trigger either worked or it didn’t, anyone had this kind of issue with optical triggers?
If anyone has an unwanted known good trigger I could buy it might sort my problem!
I was going to test it with a Piranha optical trigger that I had but I can’t find it!

Julian

[cliveyboy]

Thought I might update this old thread with my own experience.
I had a new Luminition Optronic system on my Sprint. It ran along side a high performance coil and new ballast resistor etc.
The engine had been rebuilt and so were the Dellortos, new Magnecor leads fitted, but it was always a bit reluctant to start up and ran lumpy and fouled plugs. Eventually it got to the point where it was cranking for ever to get it started and then would not tick over easily.
I decided I had run out of ideas so put it into a local classic car garage.
They spent a long time working on it with long test drives (it actually cut out on one of their early test drives). Eventually concluding that the Luminition was faulty. (It was in the middle of lock down so could not get it sent back to Luminition for checking).
They also found a couple of other electrical issues and so not sure if that might have caused problems for the Luminition.
We swopped everything over for an Aldon system and went back to a standard coil and No ballast resistor.
The car runs better than it ever has. Fires up cleanly, ticks over nicely and accelerates well. Done about 1200 faultless miles this last year with a big smile on my face.
Whilst I cant point to an exact problem. My conclusion is that if fitting modern electronic systems they can be more sensitive and unforgiving to old car electrics. So make sure your car electrics are OK, wired properly, with no voltage drops or shorts etc (I thought mine was OK). Also I might have chucked too many performance bits at the problem with high capacity coil etc which probably masked the simpler underlying electrical issues and despite supposedly being compatible the various components might not have been.
Clive

[Andy8421]

I have had optical triggers be sensitve to both temperature and vibration. They have worked fine on the bench, but fail on the engine.

In my ownership, the magnetically triggered ignitions seem to have been more reliable.

[69S4]

I think that's why I've stuck with points despite the 'fit and forget' advantages of electronic systems. I may need to fiddle with them every now and again but it's been a long long time since I was stuck at the side of the road because of points failure (and that was a condenser, not the points themselves). Given the low mileage and cosseted lifestyle most of our cars live these days as well as the constant trickle of issues with aftermarket ignitions that turn up here and in many other forums, the devil you know looks to be the better option.

Anyone any thoughts on why aftermarket systems seem to be, well, unreliable seems too strong a description, maybe 'inconsistent' might be better. I'm sure there will be people whose aftermarket systems have been trouble free for 50yrs, but equally, others seems to fail in a much shorter time frame. Plus, if points were that bad we should be getting reports of them failing as well. Is it a QC problem or design quality issue? Or maybe there's an element of incompatible pick and mix parts when they're being fitted. OE systems on modern cars don't seem to suffer from ignition breakdowns so why are our simpler ones troublesome?

[marode]

It ran along side a high performance coil and new ballast resistor etc.

I‘ve had very similar problems as you describe with my S2 Esprit and its Lumenition ignotion. Misfires after 10/20minutes, fouled plugs and so on. After years of headscratching and swopping parts it turned out that I had fitted a wrong type of coil for the ballasted ignition. You either use a 3Ohm coil in an unbalasted or a 1.5 Ohm in a balasted system. The tricky thing on the Esprit was, there is no balast resistor visible at first sight, because it’s using a „resistive wire“, a piece of wire with a certain resistance. Anyway, when using the wrong type of coil, you get that sort of issues as you described. The car may run, but not as it should. So be aware with fitting any „high performance“ coils that may not suit the existing system.

[john.p.clegg]

The only problems I had with the lumenition system over the years was with the 3-way connector not making a good connection , at times..

Sorted by having a " poke" with a fine point to open the male pins and a gentle "setting" of the female connectors.

John

[vxah]

To add to the saga! More testing with the use of an oscilloscope revealed that the control unit was intermittently not triggering the coil. I sent the unit back to Aldon and after some testing they confirmed that it was faulty. Even though it was now outside of the years warranty they sent me a new unit foc.
I fitted the new unit but, sometime later the fault was back! Testing again showed a faulty coil control with no loss of signal from the optical trigger. I sent the unit back again and after a long winded test test they confirmed it was at fault. Aldon had no units in stock and said they would send me a new one as soon as the next batch were produced. A few months went by and a new unit arrived again foc, I fitted it and all seemed well.
That was until a long drive revealed a “hiccup” during acceleration where the tacho needle drops like a stone even though the engine revs do not so, ruling out a fuel or ht issue. I bought a new coil and fitted it as I only used my spare when I was previously searching for the fault. I drove the car on many occasions with no issue.. until I went to Malcolm Rickets open day! Car played up so badly on the way after about 20 miles that I considered turning back, but I didn’t! On my way home, no problem!!
I have another one of the Aldon Amethyst units on another car that has never missed a beat, it’s an earlier version that doesn’t have the multi plug close to the unit so, my plan is to see if Aldon will send me a multi plug set so that I can swap out the units and see what happens?
I’m almost ready to throw in the towel on this and if I do, I think I should look into combining a fuel injection system with the ignition but I suspect that will be in the region of £3k with heritage tb’s?