Okay, you had the engine at idle and when you reconnected the purge valve opened? If that is correct, then you have a problem. The purge valve shouldn't open at idle on that engine. Take it for a drive and get it warmed up, Still have the bad idle? Yes - unplug the electrical connector on the purge valve. Idle improves? Yes, you need to look at the harness to the purge valve to see if it has a problem. It is a PWM signal normally so if you unplug the connector and connect a test light to the ground side of the connector (dark green wire) on terminal B and then touch the light to the battery with the key off, there should be no light as the ECU doesn't hold the valve open. If the light is on, the wire has a short to ground somewhere. Now start the engine. The solenoid will normally be off at idle because the engine doesn't need the extra fuel vapors at lower speed because it can cause rough running. If the light is on, then it could be a shorted driver in the ECU. For that you would need a scan tool and oscilloscope to test the control signal on the same connections.
You would connect up the scope and then use the scan tool to command the valve to different percentages. If the signals match, then it's okay, if on the other hand the output stays at say 75% regardless of the command the driver transistor is bad, and you replace the PCM.
Oct 25, 2023 at 3:22 AM