'86 honda accord 4 cyl...runs very rough as though missing on 1 cyl ...when removing plug wires 1 at a time each 1 removed makes engine run worse except for #1 cyl which when removed smooths engine out ...power returns... rpms go up . Do I have a bad spark plug on that cyl ?

Check what's called the map sensor. Advanced auto parts can help with that.

It is 1-3-4-2 with No 1 being at the timing belt and crank pulley end.

Have you actually checked fuel pressure, and the output of the coil ?
How good is the cap and rotor ?

the first thing i would do is a compresion test remove the spark plugs attatch a compresion guage this will tell u if one or more cylinders are low on compression this can be caused by a number faults.if the comp test is ok then replace the spark plugs if that doesnt fix the miss remove the spark plug leads and sit them back on the plugs start the engine then using insulated pliers remove the leads one at a time the bad ones wont make the engine run different when removed if all leads are good then replace the coil or coilpack if the engine runs seperate coils for each cyl then remove the bolts holding them down start the engine and remove them one at a time if they are faulty the engine wont change if the coil is good the eng will run worse when its removed if your engine runs a distributor the rotor button and cap may need replacing a damaged or corroded cap can cause a miss and loss of power if all these things are ok then you may have a fuel problem if the engine is fuel injected and you can remove the plugs without to much trouble start the engine remove and replace plug and as with the spark plg leads the faulty injector wont make any difference to how the engine reacts. if when dissconected The plug leads or injector that is working ok will cause the engine to run worse when reconected it will run better if it makes no difference its not working and needs cleaning or replacing

most likley a ignition coil is failing, is unfortunatly common for the A33 maxima. these engine have 6 coils, one for each cylinder. the only way to work out which of the 6 is the faulty one is to remove the little cover over the front bank of spark plugs, has 4 allen key bolts, then you can see the front 3 coils and the rear 3 are inbetween the manifold pipes. each coil wiring will have a button/leaver on the connectors (i think they are green) and if you push this in will release connector.
when the engine is missfireing unplug one coil at a time then reconnect after. if the engine runs worse that coil is working. if you unplug 1 that makes no change, that is the the one thats not working. replace the coil and the spark plug.
do not worrry, there is only 12volts at these connectors, not spark plug voltage

CHECK TO MAKE SURE THE WIRES ARE ON CORRECTLY, IF NOT, THEY CAN CAUSE A MISFIRE PROBLEM THAT WILL MAKE YOUR ENGINE RUN ROUGH!

possible motor mount old hondas don't have strong stock mounts

The a/c makes it worse because you are asking the engine to pull a load missing one cylinder. If you have alternate transport or like working on a hot engine you can take number 3 wire to the autoparts and get one wire to match length. You may want 1 plug in case wire doesn't help.

i would first check the timing and if that does not fit i would take the cover back off and look at the belt for a bad or missing tooth

you dont need to ground your ht lead, infact that could damage your ignition system, if in fact removing it from the plug does make it worse you then know that this cyl was firing and that ignition on this particular cyl is not your problem.