Stalling Diesel & Oil Consumption

[mikep]

My 1982 300SD will stall just after cold start then it runs fine after a few minutes. The idle speed in Drive is to low and will stall when the compressor kicks in (I just installed a new compressor). The RPM is about 600 at idle in Drive and feels like it is going to stall sometimes, 750RPM in Neutral. The car has about 400,000 miles on the original engine. Overall it runs great except the oil consumption is high but no blue smoke. I use Quaker state 15-40 Diesel and 5-50 synthetic in the winter. Generally no problems starting in the winter unless it is very cold, in which case I plug it in.

Just had the timing chain replaced and valves adjusted, new air filter etc...

How can I adjust the idle or would someone have any other suggestions.
Any ideas what is causing the oil consumption beside the high mileage.

Thanks,

mike