KitCarlson, still fighting... Options

[McMark]

I'm still struggling to get my KitCarlson EMS running smoothly. It's a challenge when you're tuning FI and Ignition.

I read some threads on ShopTalk Forums where Jake recommends 12 degrees initial advance and 28 degrees full advance, all in at 3000 rpms.

So I dialed the ignition controls in to these figures. Checked the setting with a timing light and what's showing on the EMS monitor seems to match what's showing with the adjustable timing light. This is a wasted spark system and I've been ambiguously warned that a standard timing light "won't work" with a wasted spark system. This doesn't make sense to me though.

The first issue I need to deal with is that the car won't rev above 4000 rpms. When I first started setting this up I had the same issue and adding in advance cured the issue. I trust Jakes recommendation and so I'm looking for other sources of this issue.



Currently my logic tells me that if the system is too rich above 4000 rpms it would respond to more advance. Spark earlier gives the rich mixture more time to burn. I'll be playing around with this idea tomorrow, but I'd like to hear what'cha got to say.

[lapuwali]

I can understand why an adjustable timing light wouldn't work with wasted spark. On a four, there are only two coils, and each coil fires once per revolution, lighting BOTH plugs. However, one plug is on the exhaust stroke, so that spark is "wasted". This means the inductive sensor will see two firing events for each actual useful event on each plug wire.

On a non-adjustable unit, this is not a problem, as it will just fire 2x as often. It doesn't care how fast the engine is spinning. An adjustable unit, however, will delay the strobe firing based on TIME, yet the scale for the knob is in degrees, not time. This means it has to guess how fast the engine is spinning, and delay the strobe for a shorter amount of time as the engine speeds up, since each "degree" goes by faster as the engine goes faster.

On a normal distributor ignition, each plug wire only goes off once every other revolution, so calculating engine speed is easy. On wasted spark, it will go off once EVERY revolution, so the engine will appear to be going 2x faster than it really is, and the time/degree curve will be wrong. You'd either have to use 1/2 of the degrees on the scale, or 2x the degrees on the scale. My brain is hurting trying to figure out which.