The Dummy's Guide to Direct Ignition & Coil-Packs etc

[Greg_S]

Guide looks really good Paul. : thumbs:

[S2central.net]

Rev03 added... Also I got some testing time today with lots of scope waveforms to capture on the next iteration. The highlights confirm a 4ms dwell time and 350-400V primary voltage. Testing involved a highly modified biscuit tin lid, but enough on that for now ;-)

Latest version is http://www.s2forum.com/forum/showthr...d=1#post819249

[UrS4boy]

Rev03 added... Also I got some testing time today with lots of scope waveforms to capture on the next iteration. The highlights confirm a 4ms dwell time and 350-400V primary voltage. Testing involved a highly modified biscuit tin lid, but enough on that for now ;-)

Paul: Might just be me but the pdf will not open by clicking on it OR by right clicking on it and trying to open it in a new window. The new window flashes up for a millisecond but then disappears.

[Val]

Opens just fine. Thanks for sharing your work.

[UrS4boy]

Opens just fine. Thanks for sharing your work.

Worked today. Go figure.

[S2central.net]

Quick video of testing yesterday - http://youtu.be/CGXY2rDG3j4 - for the uninitiated, those pulses get closer together as the revs rise.
Note how the ignition pulses from the ECU (for cylinder 1) stay the same width (yellow trace) and the scope picks up the ~400V spike on the primary winding most of the time.

[S2central.net]

Rev4 attached has some more screen shots from the 'scope testing done in situ yesterday along with a bunch of fault-finding steps.

Next stage is to hook up the emulator to the ECU and verify that I have found the dwell table and do a bunch more bench tests... someone donated a set of OE coils & loom to scientific research which is going to be very helpful - especially now I can simulate the ignition trigger signal with a test set.

[Henkjan]

wow, you update them faster than most people read

.... from the 'scope testing done in situ .

now you are in writing mode, I would really like a sort of "dummy guide to use a scope on your S2". I have recently bought a scope (mainly for my audio hobby, but thinking it will be useful for the S2 as well), but have no clue on how to use it

[S2central.net]

Just look at the scales on my pictures - that shows timebase of interest for engine signals... and voltage levels on the two inputs. A good modern scope will generally get you pretty close with an 'auto set' button. However, suggest you search youtube etc for instructional videos if you are really new to such devices.

[Henkjan]

... However, suggest you search youtube etc for instructional videos if you are really new to such devices.

will do this when I have my workshop ready

I have this youngtimer:

[S2central.net]

That one reminds me of school physics lab, but it's actually perfectly usable for car applications. To get started - set timebase to 50ms and connect probe 1 to G28 (rpm) and set range to 5v per division. Setup for ac coupling and you should see nice sawtooth wave when engine idling.

You need to experiment a bit with trigger levels etc for the G4 pulse and ignition triggers depending what range you are looking for.