External ignition amplifier connection - subpage of MembersPage/ChrisGerhardt/ChrisNotes
I bought a capacitive discharge ignition (CDI) amp to strengthen my spark delivery, but help is needed to connect it to and make it work with genboard
Chris, several signs indicate that Mallory forgot to put a capacitor on the input. The fact that the manual say that you MUST keep the capacitor in a points setup is proof enough. Getting a points capacitor and fitting it between the trigg wire and gnd will most likely solve the problem. -Jörgen
I got the cap and wired positive to the ignition amp trigger and grounded the case of the cap. Nothing changed. I still do not get anything. I am trying to get in touch with Mallory Engineering to see if they can help.
Information for Mallory HyFire? IVA CDI Box
All of the below information is available at the link below. It has wiring for multiple different types of setup. I simply want to trigger the Mallory Box Directly from Genboard IGBT. I am having trouble with lost spark triggering it from the Edelbrock igntion module so I want to eliminate extra wiring and parts.
Connection proposal - to be reviewed
Figure17 on page10 is closest to what I think we need.
- RED: switched +VBatt (+12V, node15)
- long RED: continuous VBatt (+12V, node30)
- long BLACK: GND
- small black: unused - black according to manual, but in fact purple. The purple signal measured 0VDC (With key on, but engine not running)
- small green: unused - measures 4.8V DC (With key on, but engine not running)
- YELLOW: output coil+ (appr. 350V DC : please measure this. Take care.)
- BLACK: output coil- (pulled to GND by the module for short time at the start of the spark)
- GREEN: GenBoard's ignition output => mallory's trigger input: a spark will be emitted at the rising edge. Measures 11.8VDC with key on engine not running. While wired to genboard and cranking, shows mean voltage less than 5VDC which indicates that Genboard pulls it down (to GND, but only for the dwell-time). Actually, 5V sounds a bit too low. Assuming VBatt=8V means pulled to GND at least 40% of the time, which is high for cranking RPM at given ign_dwell... settings (even for a v8).
I connected as suggest above without the cap, and no spark was emitted. I have to go the the parts store to get a points style ignition capacitory.
- There is apparently no anti-theft input (neither in the manual, nor in reality.
- indication of power (eg. LED): ???
- indication of trigger-input received (eg. LED): ???
Continue (well, start) to document the rest of the system and move on to testing.
- Exact EC36 pins: Pin 10 is used for ignition trigger.
- h= .. ..
primary_trigger=FF secondary_trigger=FF tooth_wheel=00 trigger_tooth=00 another_trigger_tooth=1E crank_minper=50 tooth_wheel_twidth1=FF tooth_wheel_twidth2=FF cam_sync_r_edge_phase=FF cam_sync_f_edge_phase=FF reset_engphase_after=FF ign_tdcdelay=00 ign_dwell14=20 ign_dwell6=40 ign_crank_advance=48 ign_out=70 ignchmax=00
- Why do we think the ignition module is good?
- The engine ran with the CDI being triggered by the module, but still had problems dropping fire intermittently. The module is the common part that I want to eliminate and replace with CDI only.
Cranking the engine is not necessary,
- make a spark-gap between the wire going to the distributor and GND
- you can use a sparkplug - but don't hold this in hand
- or you can just use a wire placed appr. 1..2mm far from engine GND: the spark will go from the wire to the GND at the shortest path (again: you don't want to be the shortest path, and anyone with pacemaker does not want to be close at all)
- mdn01 will emit one spark (using configured dwell and VBatt: normally visible and hearable) on ignition channel h=.. xx .. .. .. .. .. ..
- another way to try triggering is to connect the green wire for a short while to GND (IGBT or GenBoard does not need to be disconnected for this experiment)
If directly connecting IGBT output to green wire does not work
I think directly connecting should work, either the module is trash or something is misconnected or misconfigured that will show up soon as documentation is made.
You can also try:
- a capacitor between green wire and ground. Very unlikely that this would fix the problem (this was tried since, and did NOT help), but costs little to try. beware that, eg. a 10uF cap will delay appr. 500..1000 Ohm * 10uF = 5..10msec (unacceptable). So cap must be 10..100nF range:
- I would definately use a capacitor meant for this, which means a capacitor for a car with points ignition. -Jörgen
- if that fails, another thing to try: a 1k pullup of the IGBT output to 5V; and a min. 10uF capacitor between IGBT output and "green wire" (this is the "series" cap). This is also unlikely to fix the problem.