I have a problem with my '93 940 turbo. This started out of the blue with no warning.

When I depress the gas, the car hesitates severely, backfires a few times and if I keep pressing the gas, will stall. If I back off the gas I can usually accelerate very slowly and once I get up to speed it is ok. When this is happening the idle goes up to 1300 instead of the normal 750.

I get codes 1-2-1 (Faulty signal to/from Air Mass Meter), 3-2-2 (Air Mass Meter wire burn-off signal absent or faulty) and 2-3-1 (Fuel trim (lambda control) too lean or too rich at part load).

I recently replaced the spark plugs, wires, ignition coil wire, distributor cap and rotor, cleaned throttle body, cleared blocked vacuum hoses and flame trap holder (turbo engine).

I have verified that no vacuum hoses are loose or leaking. The plugs are all correctly torqued and the wires are on tight. Bosch cap and rotor. Ignition coil wire on tight.

When I disconnect the AMM and restart I get the same symptoms. When I disconnect the O2 sensor I get the same symptoms. When I disconnect the Throttle Position Sensor I get the same symptoms.

I have looked over the FAQ, but no solutions are staring me back in the face.

Any ideas?

My thoughts are maybe AMM. You hear a lot of different opinions on how often AMMs go bad.

TPS? from the throttle body cleaning.

Fuel Filter. Last change not known.

If anyone is familiar with this problem I would eagerly anticipate hearing your thoughts and ideas.

Thanks a million,
Ian