OK, forget electronic correction.

With the EHA disconnected, what is your problem? Can you adjust the mixture to a good idle? Can you go to far rich and make it run bad? Can you go lean and make it run bad? Is there a better point in the middle?

If you had a vacuum leak and you did the above mixture movements, there would be a point where you corrected by going richer and overcame the extra air. If you did that mecahnically and you had an air leak you now would be running much higher rpm than idle should be.

Remember that air is what control rpms, not fuel. The highest rpm for any amount of air going in will be the amount of fuel that gives the best mixture.

You are right that you must solve your mechanical fuel problem before worrying about the electronics. The KE system does just fine warm without electronic control. BTW, are you sure you have an O2 sensor. Many euro models of KE didn't have catalytic converters. Only cars with TWC (three way cats) had O2 sensors.

Look at your exhaust if in doubt. The sensor will be obvious in the exhaust if it is there.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician