Thanks Mr. DeWolfe for getting back with some very insighful observations!! I have the schematics for 84 and other volvo reference but am not that great in decifering them. I appreciate greatly the time you took to look into this!

Yes, the car is an early 84 with LH2 and a single wire O2 sensor.

You may be on to something regarding the blue wire. It >>IS<< a CA car and there was no EGR valve under the hood?? My 90 wagon came from CT but HAS an EGR valve. So I may have 2 CA 240s. I found the blue wire resting along the block towards the distributor, but I'm not sure if that was its original resting place. What would you recommend I do with the wire...remove it?? Right now I have it wrapped around the fuel hose along the firewall just to keep it out of the way.

The idle position switch was unscrewed when I cleaned the throttle body and my intention was to remove it, but after I saw the bent screws in the shaft of the throttle plate that needed to be removed (??) to remove the switch, i didn't want to risk one of the screws snapping, so I left the switch on and reset it properly. It clicks as soon as the throttle pully is moved off idle.

The purge cannister was not touched so I can't imagine it going bad or out of position. I did check the hoses and they all looked firmly attached. There is no hose attached to the grimy nipple at the bottom of the cannister, only at the top.

You are correct on my error in the pin numbers at the ICM connector. I got my temp sensor BL 2 mixed up with the injectors GN/W 13. Too much blue on my mind!

My intent was to check for continuity with only the #4 injector circuit to the ICM connector since there was uncertainty there. I placed my probe at the GN/W pin of the #4 injector and at the GN/W 13 pin of the ICM connector. Since the injectors are all wired together, they all gave me the same screwy results at the ICM connector, but again, i just wanted to make sure that there was continuity only with #4 because there was little change if any in engine speed when unplugged for this injector. How would I isolate the injectors otherwise? Performing this same procedure on the parts car harness gave me predicatble results, as did the backup harness. What do you feel would cause the meter to buzz on every other circuit of the ICU connector when probing the engine side GN/W pins? BAT negative was detached.

As much as I hate to redo my work when I took such pains to do it right the first time, I'm prepared to give the harness swap a try and have reserved sat for it. BUT any further suggestion will be tried!!