85 740 GLE Non-turbo stalls when put in gear or push on accelerator

You may have an old engine oil, why don't you have your car service and change oil and oil filter as well. Then if the problem still appears, then that's the time to start tracing where the problem really starts.

I'v had that same issue. It turned out the be the fuel pump. I replaced the one in the tank as well as the one under the driver seat under the car.

It is not adjustable, it is computer controlled. Clean the throttle valve and that should help./

Can you borrow an ignition coil and/or control unit for a day or two to check for the misfires?
The "Secondary Air System" should not be the problem since it merely is some air that gets blown into the exhaust line to increase start-up speed of catalytic cleaning. P0410 indicates a malfunction of this additional air system. This might be caused by the non-return valve in the air flow, the lambda sensor, or the air pump (which the turbo does not have, as far as I know). The valve is not too easy to get to but is quite often the source of the problem.

Good luck
Ingo

I have the exactly same issue. Did you solve yours?

Fuel Filter yes! Then ck fuel pressure. But it may be a Converter.

you need the key volvo can orde one by the vin

Have you tried replacing the fuel filter? It is located under the cars center on the left side ..

You will find it alongside the main high pressure fuel pump on a metal support plate held up with 3 bolts.
Remove the 3 bolts with a 10mm socket wrench to lower the plate. Place a catch pan below the filter to catch any leaking fuel.
Be careful not to get fuel in you eyes or running down your arms. Remove the 2 bolts holding the banjo fuel pipe connections to the filter.
Note the direction of the filter.
Loosen the clamp holding the filter to the support plate and slide out the old filter.
Install the new filter in the same direction as the old one and use new copper sealing washers on the banjo connections.

There is one in the fuel tank on my 740GLE (1989) and one near the fuel filter underneath near the driver's door.

Check the turbo waste-gate actuator spring for proper tension.