Here is a link to an article on fixing vacuum leaks.
http://www.peachparts.com/Wikka/M103VacuumLeak
I suggest you replace all the plastic 4mm vacuum lines and rubber elbows, the idel air bypass hoses, the injector holders and seals. There is a large rubber section under the CIS horn that may also leak.
http://www.landiss.com/mixture.htm
and this one on changing the mixture and monitoring it with a voltmeter, preferably one with a duty cycle setting, available at Sears for about 30 bux.
You need to check the EHA current, the small black box on the side of the fuel distributor.
Please post your emission numbers.