It is not a difficult fuel injection system, and half the world used some type of Bosch fuel injection.
Not just BMW and Mercedes, but Volvo and Cadillac as well.
But there are still a lot of things to cover.
The first thing you would want to do is know if the fuel pressure is there.
That will tell you if the relay, pump, etc., is working right.
To do that you could listen to the pump, or pull the bolt out of the test port outlet on the fuel rail.
It would be even better if you bought a gauge and could see of the pressure was nominal, ( I think about 40 psi for that model AFC injection.)
The fuel filter and gas tank purge valve can also cause this symptom.
The filter just do it, but with the pure valve listen for whooshing in or out, when opening the gas cap.
Should have neither.
Try an inductive timing light or spark tester to see if the problem is ignition.
Check for loose hoses, cracks, etc. that could cause manifold leaks. (big rubber bellows tube around air box is common to crack and you can't see it unless you flex it)
There really is not much more. With an ohm meter you can check the air box and head temp sensor. The air box has big plug on it that has many individual circuits. 2 leads are intake air temp. They are around 300 ohms, but I don't remember which leads. 2 also pulse closed and open as the box flap is progressed. If you really need more, I can try to find more details. But the fact it works at home means it is not likely electrical.