'87 BMW ignition system died

This sounds similar to the system in K-jet Golf GTIs. I have to say, the only thing I know about it is that very few people know much about it...

Is there a reason why you can't fit EDIS permanently?

Nedavno Doki napisa:

It looks relatively simple to me. You have pulse generator in the distributor that tells ignition control unit when to fire ignition coil. Not much that can go wrong. Just one of these three. I am going to test it further, but it's very cold out now. I just do not want to throw money at it as I am fitting EDIS.

I will fit it permanently, but I just ordered MegaJolt Lite Jr. - Programmable Ignition Controller that tells EDIS what ignition advance is at any given moment. So I can not drive my car now.And I wanted a backup system, Ford's EDIS is probably reliable, but I do not know about MegaJolt unit. I wouldn't like it to fail in the middle of nowhere. EDIS does have a limp home mode, but still...

If you left the original coil connected, there's every chance the high voltage has arced from the HT terminal, across to the LT terminals which in turn would put a few kV through the ignition control unit and associated parts. Are you sure the spare ignition control unit is good? If you are, then all you can do is try a new pulse generator.

When working on electronic ignition systems, if you plan on turning the engine with the HT leads disconnected, you should disconnect the LT terminals to prevent the coil from firing.

Nedavno moray napisa:

I did.

I did test it when I got it, and it worked.

:-)

I wonder if I can use 1.5V battery and touch (for a brief moment) connector for pulse generator at the distributor and watch for a spark?

I learned this the hard way :-(

Have no worries - the technology is the same as any other ECM.

Nedavno Conor napisa:

That's good to know. But it has that MAP sensor (Motorola MPX4250AP 2.5 Bar pressure sensor). How reliable is that? Do you have MegaJolt?

The Megajolt unit is as reliable as the bloke who solders it together, which is why I bought mine already assembled ;) Mine has been 100% reliable after a few thousand hard miles.

I had the dizzy and all the old ignition gear running alongside for a while as a backup, but never needed it.

Don't worry about reliability, even if it did break, the real cleverness is in the EDIS unit, which will get you home even without the megajolt connected.

If you need a Megajolt, the bloke who sold me mine has a new one already built and for sale ? :)

I personally don't but a lot of people in the modified classic Ford scene do and nobody has had a problem with it.

Nedavno Tony Bond napisa:

I am confident that I can do it well.

That is what I had in mind. If I can fix my original ignition cheaply I will. If not - I will remove all of it.

I know, I already got it running on EDIS, I am waiting for MegaJolt kit to get here.

To late, I ordered one :-)

Nedavno Conor napisa:

I only found "Mine has been 100% reliable after a few thousand hard miles" (as Tony wrote below). What about few tens of thousands of miles?

Its not a good idea to run the coil with the HT lead disconnected. Even in the days before electronic ignition the coil would get very hot after a few minutes and possibly flash over inside and cause carbon tracking between windings. These days there is a big risk the ignition electronics will be damaged by the very high voltage floating around the primary of the coil.

Graham

I reckon if it can handle a few thousand miles of the ravages of British roads in a "seven" it can handles many thousands of miles in a more sensible vehicle.

stop worrying about it :)

Nedavno Tony Bond napisa:

OK, thank you. :-)

Nedavno Graham Harvest napisa:

When weather improves a bit I will do more tests and post here what I find.

Nedavno Graham Harvest napisa:

I've done some testing today.

I connected battery + to the 15 terminal of the ignition coil, terminal

1 to the one side of the capacitor, and the other side of the capacitor to the ground.

I then connected one side of a wire to the ground and with other side touched terminal 1. No spark at the grounded spark plug connected to the HT lead from the tower connector of the ignition coil.

So it seems that at least ignition coil is toasted.

Can I put old (but working) ignition coil used in a car that had pints in the place of this TCI coil? Just for a short time to test if I fried anything else?

I also read somewhere on the Internet that I can connect test light to the terminal 1 of the coil to see if it blinks while engine is cranking. Does that apply only for points ignition system, or I can test TCI system too?

Nedavno Graham Harvest napisa:

It was the ignition coil that died. I just fitted new one, and it's OK now.

Nice one.