Chrysler Repair: Code 31 canister purge solenoid problem, rough idle when cold, light flickers, emission control system

Question
I'm working on an 88 new yorker 2.2 turbo. I have just replaced the fuel pump, fuel filter, map sensor, timing belt, cap, rotor, plugs and wires. Now it will start and run, but its a rough idle and feels like its only hitting on 2 cylinders. When you rev it it will rev really rough and the check engine light flickers like its trying to die. If you dont keep playing with the gas it will die. Then after a few minutes of keeping it running, the check engine light will clear and the car smooths out and will idle. The only trouble code it will give is a 31, purge solinoid circuit. Where is this solinoid and how can I test it to see if it is the problem. What does it do?  

Answer
Hi Duane,
Ooops, I just re-read the manual and see that I reversed the valve function when it is energized/de-enegized. It is normally open, but closes when energized. The time/temp function of the valve is correctly described, but the grounding of the pink trace was reversed in my description to you.
Roland



Hi Duane,
The purge solenoid controls the evacuation of the fuel vapors stored in the charcoal canister which is part of the emission control system. The solenoid is (I believe) located on the right side inner fender shield and it the forwardmost relay/solenoid mounted on that side. It has a 2-wire plug which has 12v on the dark blue wire when you have the ignition switch to "run" position. The other wire is pink trace and is attached to the engine controller 60-way at pin 54. If you don't find the solenoid where I described it to be, check the right side strut tower for a similar 2-wire plug of the same colors.
Its purpose is to open the vacuum line from the canister to the intake manifold (when the pink wire is grounded), and that happens AFTER the engine is warmed and as well after a time delay of a few minutes. So it may well be that your rough early idle is due to a solenoid pink wire that is grounded all the time OR the solenoid valve is stuck open so that it is allowing vacuum to suck at the canister before the engine is warmed up. When it is not grounded, the pink wire may either have 12V on it or be floating, I am not sure which, but in any case you should not find it to be grounded when you start the engine cold. You could test the solenoid valve by putting 12v and ground jumpers direct from the battery and see whether it clicks and whether the vacuum line nipples indeed open the valve (suck), and then remove the jumpers and see if the valve is then closed (suck again). So those are my suggestions and an explanation as to how it is supposed to work. Please let me know what you observe and how this is resolved.
Roland