brewtoo,

I didn't try reading at the diagnostic plug because I don't have duty cycle on my multimeter, nor do I have a dwell meter. I guess I shlould look for one in future. I tested the 02 sensor and it had failed. I relaced it with the Mustang sensor and all is well.

Steve,

I guess I didn't understand the accuracy of the mechanical injection. I assumed that since they removed the control system from the all mechanical injection and replaced it with the EHA system that only very crude mechanical injection was left in place. Now that I have the new O2 sensor in place and get to watch the system in action I am very impressed at how accurate the mechanical system is, at least at the conditions that I have observed it at.

I watched the EHA current go from +10ma on cold start slowly move to -7ma when warm an adjusted to approx. -3ma. My concern is that I do in fact have the open circuit running slightly rich. I assume that at cold start the mix was lean and the EHA current (+10ma) was richening the default setting. As the engine reached operating temperature the default mix became rich and the EHA was sent -7ma to lean it out. Therefore setting to -3ma ensures a slightly rich default setting (open circuit) for WOT operation. Is this correct?

ps. Thank you both for all your help. I have a lot to learn and so far am enjoying it immensly.

Jorg