1988 Onan MDL3 15KW - Fuel Injectors

I just finished a full service on the generator. It has just under 2000 hours. Once completed the generator was started and everything checked out, it ran great. The service tech said that the injectors were leaking. Since the manual calls for new injectors at 2000 hours I gave him the okay to remove them and have them rebuilt. It took just over 3 weeks for him to return and install them. Once installed the genset was started and I noticed some light smoke, seemed whitish in color. When a load was placed on the genset it puffed out some more smoke and then once again just seemed to remain lightly. I had never noticed this before. The service tech did agree that he had not noticed any smoke before and acknowledged it was not normal. The service tech contacted the company that rebuilt the injectors. He then told me that they usually resolved the problem by advancing the timing. This did not make sense to me. I asked him to try to gather the old parts and have the injectors checked and tested again. This time he will be taking them to another party for checking. He said that the tips were replaced but the same shims were used. By the way, the original injectors are absolete and I am unable to locate any information specific to injector sizing for each model.

My experience is mostly with 4 cycle automotive gas engines. I know there are plenty of experienced members on these forums and i look forward to your feedback.