Kelly,

I’ve attached a photo of the parts added.  Visible on the circuit board are the components for two of the four injector pulse channels.  On the back side of the board is a duplicate set of parts.  This adds up to a total of 80 discrete components to do the job, not to mention the functional components internal to the four timer integrated circuits.  As mentioned, this was just a “proof of concept” endeavor and is more than likely not the best way to do this. 

The oscilloscope trace shows the resulting injector pulse signal.  At 8.2 ms, a very short low to high transition is seen.  This is the end of the EC2 pulse which is detected by the board.   The injector is then turned back on by the board for the added 1.2 ms.  The injector cannot respond to the short time between the two pulses and remains open the entire time.  It is possible that the two closely spaced pulses may upset the EM2/3 determination of fuel flow and be a problem with that.

On the surface, it would seem to be possible to add the equivalent of “+1.2” to a line in the firmware code or add the few machine level instructions it would take to do this.  To accept this mission,  Tracy has to weigh the cost/benefit ratio of doing this.  It is possible that limitations in the controller memory make this a mission impossible.  If the programming changes can be made, his already proven hardware would be used without the addition of all those extra parts.

I have no desire to produce this hardware or profit from it.  The goal is to possibly make the EC2 user’s (and Tracy’s) life a little easier.  If an update resulted from this that reduced Tracy’s customer assistance  phone call volume to the point that he felt neglected, we could all take turns calling him once in a while to see how he is doing  ;>)

Seriously, though, Tracy will more than likely come up with something better, like he always does.