I have an 85 porsche 944 ...smoke, oil, bad engine temp

Fix your car right away, by clicking the link
https://www.reliable-store.com/products/1982-1991-porsche-944-944s2-944-turbos-951-service-repair-manual

to check that substitute the ecm with a known good unit

to me could be a gasket problem if you are blowing smoke when applying gas. just a suggestion. have you checked the oil? to see if milky? keep me informed please. Thanks.

definitely use a high mileage, synthetic oil for foreign made cars appropriate for a 4 cylinder engine.

you have a starter thats dragging and you will have to replace it (the starter thatis.)

This could be just old oil and dirt getting hot for the first time in a long time. My 928 will also do this for a while if not driven through the winter, but clears up after a while . To be safe I would clean the area that you see the oil at, and then see if when you start it more oil collects. It could also just be comming from the cam housing(looks like valve cover) check it out well, these are tough engines.

White smoke suggests to me that your brake master cylinder may be leaking into your booster and the diaphragm may be split, thus allowing brake fluid into the engine.

Hello;
The white smoke is from coolant entering the combustion chamber(s). Coolant can enter through the water passages sealed bu the head gasket. You have probably blown a head gasket. You should check your coolant level. You may have acracked head if you continue to drive it and overheat. The temp gauge only reads when exposed to coolant, not air. Take out thhe spark plugs and look them over. A white glossy apperance will indicate water in the combustion chamber. You may need to surface the head once you have it removed so that it is flat. Hope this helps.
Thanks;
Rich
RPM Northwest

porches 944 start but will not keep running?

It is a common problem for the seals in the oil cooler to leak and allow water into the oil. I'd check this first, there should be a procedure online somewhere. Try googling "clarks garage"