is plugged in? There are no vacuum leaks whatsoever; all circuits leading from each of the 5 ports from the throttle body have been checked. This is also validated by the fact that the engine will not idle by itself when any significant vacuum leak is occurring. When plugged in as normal, the M.A.P. sensor operation has been tested in real-time with an OBD-1 scanner, and it changes the reported absolute pressure, and thus its voltage output (at least, through the vehicle's OBD-1 diagnostic circuit), when a typical engine vacuum is applied to it with a hand pump. However, the engine will not idle and dies when the M.A.P. sensor is plugged in, but idles perfectly and smoothly returns to idle speed from higher RPM's when no M.A.P. sensor is plugged in. The throttle position sensor has been replaced and functions with real-time monitoring. The automatic idle speed motor has been replaced and functions with its incremental steps as expected. The throttle body temperature, coolant temperature, and battery voltage are all being reported at their expected values. In summary, the MAP signal causes problems, but removing it removes the problem. Vehicle: 1989 Dodge Omni 2.2-liter, non-turbo.
The new M.A.P. sensor DOES NOT solve the problem, but UNPLUGGING it (electrically) does solve the problem. It's output voltage is somehow, for some weird reason, being "mis-used" somewhere.
The new M.A.P. sensor DOES NOT solve the problem, but UNPLUGGING it (electrically) does solve the problem. It's output voltage is somehow, for some weird reason, being "mis-used" somewhere.