Update to rough idle...
Finally got around to taking out the idle motor and giving it a good cleaning and a quick spray with WD40. It now starts up fine (cold) goes into a slightly raised idle for a few secs and then settles down to what would be a normal idle. Except that there is shaking and I hear slight mis-fires going on, like pop....pop..pop....pop..pop..pop...... and so on. If I raise the engine speed it seems to clear up, but there is some missing going on still. It almost seems like I have a faulty plug or maybe the plug gap is too wide? These Nippon-Densu plugs were installed about 2 weeks ago. Where should I go from here???? Thanks!!!!!!!!!
Items replaced so far....
plugs
plug wires
rotor
one fuel injector (with a good used one)
all injector o-rings and caps

Also check the flex hose in btwn the TB and the AMM. My wiring harness rubbed a hole in it that couldn't be seen until removal. With the hose removed you can cover one end with your hand and look for light leaking in, showing an air leak.
-JonB. '83 245DL

I've not been following.

Have the intake manifold gasket and injector o-rings been replaced along the way?

If you are still on your original intake manifold gasket, you are on borrowed time, and those can cause a popping misfire sound when they leak (at least, mine did).

Did the "missing" start when you put in the new plugs, or has it been there all along? If it just started, I suppose you could have a defective plug or wire, although that would be a longshot. Have you checked all of the spark plug wire connections? It's easy to have them not get seated in far enough.

When was the last time you cleaned your throttle body?

Missing started before replacing anything. Have not cleaned the throttle body yet. I think I will need a gasket before cracking it open, right?
It's just that I thought the popping meant uneven ignition of fuel. I have checked all plug wire seating as well as replacing the cap and rotor and reseating those wires as well.

Haven't been following too close. Did you clean the Throttle Body?

including the Hoses runnig from the Flame trap to the Brass nipple on the Throttle body.

Unscrew those nipples if you can't get Carb cleaner to run through them. Running a small wire down the Nipple might not help. The hole in the Throttle body is offset from the hole in the nipple.

You didn't mention changing the Cap. just the Rotor.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

Yes, took the throttle body out, cleaned it with carb cleaner and found one small inlet hole plugged up. Ran small wire through it and now I can blow through it just fine. Put back together (with new gasket) and now it starts fine when cold, idles down, and there is no popping until it warms up. When warm the engine idles too high and has missfire sounds like pop......pop.pop....pop but fairly soft. It runs ok on the highway but is too high at idle.