Could be a number of things..... You could have damaged the injector seals when installing them.... What injectors did you install because a number of companies are selling poor quality injectors.... You could have poor connections on the injector plugs or the PTU wiring connections.... If you changed injector size did you get the ECU re-programmed for the new injector size?
The smoke is probably oil burning off from removing the valve covers and should stop if you did a good job sealing the covers......
:i removed the plenum and painted valve covers, replaced a fuel injector :now car is shaking really bad and dies when on drive and smoke is coming from what seams to be under valve covers or around :
