I have an EM4-F in my Mitsubishi 2.6 4cyl. It's been running pretty well, but recently, things changed a bit.
Upon initial start-up, the motor runs really rough, and stumbles badly. I need to feather the throttle, but giving a pretty good shot. Not floored, but close. It will then "catch-up" and idle smoothly. It sometimes backfires when I start it, and usually smells rich and gassy.

Am I lean or rich?? is it a timing issue? The need for go-pedal tells me lean, the backfire/smell tells me over rich

Any help??

for startup put 10* timing for the 500-1500 rpm ranges, with zero values in the map vacuum adv/ret,

for idle air you will have to adjust your throttle stop screw that is located on your throttle body, possibly under a rubber plug.

for fuel you can consult the chart in the manual to figure the approximate values to enter, from here you can tweak the fuel adjustment knob a bit when idling you want about a 13/1 air/fuel ratio, a wideband oxygen sensor is the only way you are going to be able to program consistent values from this point on.

if everything is hooked up correctly and maybe a little mashing on the throttle for some airflow it should start

I have the exact same problem but when the engine is hot. It starts and run fine when cold. I have a SDS installed on a 69 Bronco with a 351W. I checked the injectors, fuel pressure, and fuel filter. All is fine. I adjusted my idle timing. If you figue it out please let me know.
Mark

I used to have a 2.6 in my Conquest. It almost sounds like the Temp values are off or the MAP values are off. I can send you my settings but I had 95lb. injectors and i ran e-85. However the values I am describing have no influence to the type of fuel used...