| I'm trying to narrow down a problem with my '91 US N/A 2+2 and could use your expertise. Idle is rough and the car has what feels like a loss of power and stutter around 2500rpm at part throttle. Felt like loss of a cylinder so I went through the typical tests. Unplugging the coils one by one I couldn't find a dead cylinder. The coils themselves all produce a spark (tested with spark plug) and the harness connectors are receiving a signal from the PTU, viewed on an oscilloscope. Injectors all sound fine listening to them using a screwdriver. I've taken the electrical plug off 3 of them (not 3+5+6 yet) and they weren't very corroded and read normal resistance. All the connectors going to the Crank Angle Sensor, Throttle Position Sensor, Mass Airflow Sensor, Power Transistor Unit, etc look alright. Unplugging the MAS makes my idle much better. Leaving the MAS plugged in but removing it from the air intake makes the engine die, so it's at least working partially. The MAS sensor elements - hot wire? - look normal and clean. Is there a way to test the MAS either with a multimeter to the connectors or by taking it apart? I tried to take off the panel with the connector held in place with 4 screws but it felt like I would break the internals. At this point I'm not sure how to proceed with troubleshooting. I was going to buy a compression gauge and test the compression in each cylinder. Also, does anyone have pointers on how I can test the harness going to the CAS, TPS, MAS, PTU, etc? Any other suggestions? I'm no expert. Thanks.
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20:54:28 01/04/11
