Car: 91 940GL B230F engine LH2.4 injection & EZ116K ignition

Have been having some trouble getting the car started (cold and hot) lately so I had the battery checked out. Old one dying so I have a new one put in. Car cranks much stronger but starting problem remains. 8 times today I have operated the starter, the engine "catches" but as soon as I release the key the engine dies. One time it took 4 attempts to start the car. It finally started with a little throttle input. When it starts, the engine idles very slow, around 500 rpm or less but it is a reasonably stable idle and the lambda light in the instrument panel is on. If I put it in reverse or drive, about 1 second later the engine suddenly revs up about 300-400 rpms and the car lurches. A couple of times I have tapped the accelerator pedal only to have the car stall as soon as I let it go. I have checked all vacuum hoses (the ones to and from the idle valve are pretty hard but have no cracks in them), hose from airbox to throttle body (no cracks). There are no fault codes. Could this be a worn/malfunctioning idle valve?

What are the possibilities?
Thanks for any help.

Brad
91 940GL