I just installed a 603 turbo IP in my '96 606 motor.

If it is unburnt fuel smoke from over fueling, it will only smoke when there is more fuel than air to burn it.
It should not smoke at idle. Over fueling at idle should only cause the rpm's to increase, not cause smoke.

By your description, your timing is correct.

Please put your car's model, year, and miles in your signature. How many miles on the car?

Why did you need to replace the IP ?

Is the smoke coming out the exhaust?
What color is the smoke?
Is it smoking at idle?
Do you have air in the fuel lines?
Is the engine making any new nasty sounds since the IP swap?

__________________
Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO