1995 S600 (sold)
OK, some of you may know I recently rewired my passenger side Electronic Throttle Actuator and replaced the wiring in both Hot Wire Mass Air Flow sensor harnesses. I also "retaught" the actuators afterwards using the input from you guys. The car runs, and starts easily when cold or hot. I notice that when starting the engine while hot, the engine pretty much roars on startup, and idles at 1500 - 1600 rpm (it should be around 600 rpm). It stays at this level for about 8 or so seconds, then I hear a very subtle valve-type pop (cannot determine location of sound), and the idle drops down to 600 rpm. If the engine is very warm, and I repeatedly shut it off and start it up again, the idle may not drop down unless I put it in gear. To be honest, I do not know if the car was doing this before I did the rewire project, but I doubt it. I feel I dislodged a wire, or a line to some kind of purge valve or something. I do not think it is tied into the actuators. I am not getting any caution lights. I did get a faulty right 02 sensor code, but I think that was in error. I took voltage readings off both the 02 sensors, and they look very similar. I cannot get a repeat of the faulty 02 sensor code either. I also am getting a code for a faulty Starter Lockout/Backup Lamp Switch. I am told that this switch lowers rpm when shifting into reverse to prevent hard trans shifts. I will try and test this component. I also notice that I am no longer able to get any blinks out of the DM anymore...not even a 1 for no fault found. But my gut keeps telling me to look deeper into this start circuit. Does anyone out there have a good understanding of what chain of events occur during startup when hot? I feel this is somehow tied into an emission / purge thing.