EL ECU query.
I have a Dec 96 Fairmont 6cyl, 97,000 Ks. Stumbles at low speed some times when moving off from kerb under light throttle, about 5 mins after first starting and backing out of the drive way or after leaving work. ALL ignition parts were replaced recently and the fault persitts. I have a Gregory manual and checking the Coolant temp and intake air temp, the manual specs 5V at the connector to the sensor when disconnected. I measure 4.6 to 4.7. If I lift the voltage at the sensor when it is in circuit, the engine idle smoothes out nicely. ( I didn't mention the idle with AC off is a little rougher than it used to be at say 40,000Ks) When the AC is active the idle is smoother and the Oxygen sensor has a richer reading. I figure if I am raising the voltage at the temp sensor the mixture is a little richer. The manual suggests that the snesor voltage being low could be the ECU faulty. Another check is for the OXYgen sensor, manual states the sensor output will be high for 40-60 seconds after starting, then fluctutes between 0.1 and 0.85V while running. With the engine idling unloaded mine sits not much above 0V, less than 0.1.
Can any one else check their voltages and forward them to me.
Ign on, Eng off, coolant sensor diconnected and voltage measured between two wires in plug.