With the ignition OFF, unplugt the Air Mass sensor. It is in the big plastic tube between the Air cleaner and intake. There is a release you need to squeeze.
If the car then starts and idles, the problem is in the air mass sensor or it's wiring. You can drive it in "Limp Home" with the AMS disconnected but it has NO power, Sometimes cleaning the plug contacts works. But it is usually the sensor. There are much better prices on line than what the dealer wants.
I wish I had known that when I limped to the dealer and emptied my checking account. Lack of an Air Mass sensor is also the reason I like my 94 940s with Regina injection.
Al
Had 79 245 D, 81 240 D, 86 240 320,000mi and running fine when traded 94 944 Green 257,503 mi CRUNCH Parted out Have 94 944 White 149,000 The New one 94 944 Maroon 135,000 mi