Thanks for the prompt response, Steve.

I am now running the car without the EHA on.

I have leaned the mixture (counterclockwise) in order to get driveability.

Before, it was bogging down on accelleration and smoking really bad.

Now,having leaned the mixture, although it is still smoking (albeit less than before), the car is driveable without the a/c on.

Idle is stable around 750 when cold but once warm, idle surges up and down between 550 and 750rpm.When stationary, feels like car wants to quit (and sometimes it does at decel).

Accelleration and driving at speeds is not a problem.But still smoking while driving.At idle, exhaust smell is strong.

So the car is running rich even with the mixture leaned.

If I richen the mixture, I can get a steady idle but the car will severely hesitate off the line (even with a/c off) and while driving, it will smoke bad and power is low.Feels like it is flooding.

This is the reason why I have leaned the mixture.Having done so, the car still smokes and gas mileage is bad (slightly better than before I leaned it).Car now consumes 44 litres having run 300km.Before I leaned the mixt, it could only do 260km per 44 litres.

So it doesn't look like a vac leak does it?From your information, I deduce that if it were a vac leak the car would run lean to begin with and that I should richen the mixture to compensate - but the opposite is true in this case.

Also, car starts without accellerator in the morning (although EHA off so no cold start) 1st try and when warm needs the accellerator to start before it catches.

I have also verified the OVP (just in case) by doing the EHA key-on value - it is 10ma with both of my OVPs (I have a good spare).

One more tip for the problem - when I got the fuel pressure regulator replaced (old one was leaking) with a used one, I got a mech friend to help retune the engine with EHA on (he richened the mixture bi tby bit and revved the engine every now and then producing billowing clouds of black smoke).By the time he finished (he richened the mixture), there was hardly any black smoke when revving.

He also turned the a/c on and tuned the car so there would not be a flat spot when accellerating.

After he finished, the car drove really well for about 15 minutes like new.

Then, it went back to feeling like it was flooding - bogging down while driving, severe hesitation and smoking (worse with a/c on).

That's when I disconnected the EHA (again) and leaned the mixture.

Could it be that the used regulator has gone south?

I am not sure how the fuel distr works but it seems to me that the regulator maintains the control pressure on the upper chamber and if it does not work right, it's like more fuel but less air - so rich running even though mixture leaned?

I'm not sure.

Please advise.

May thanks, again.