Excessive Smoke When In Drive And Idling Options

[Surinam Cruiser]

Is there somebody who can help me out with this?

I recently purchased a Landcruiser Prado 3.0 TD intercooler from 1997 (motor: 1KZ-TE, 2980 cc turbo intercooler, type: KD-KZJ95W-GKPST).

Now I experience excessive smoking when the car is in Drive but idling (like when you wait for a red light). This problem occurs especially when the A/C kicks in and the engine drops a little bit. But when I shift to Neutral or Park, the smoke disappears. The smoke is sure fuel-based, it seems that there is just not enough air to have a clean buring engine at that moment.

All filters are new, no obstruction in the air pipe, and the diesel is just normal Shell diesel.

Anybody knows what is happening here? Something to do with the trottle position sensor? And can this engine perhaps be scanned with a computerized engine scanner?

Any advice is very welcome!

Many thanks,

Dieter