ruff idle on 94 altima gxe help

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well i just picked up a 94 altima gxe and it has a ruff idle. it is running around 600-700 rpm. It will spudder on take off through first gear and then smooth out in 2nd gear and beyond.. come to stop and ruff idle comes back.

I swapped out the following:
wires
plugs
cap and button
put some seam foam in the tank..to try and clean injectors..
did not put it on a timing light

engine is not throwing out any codes that i know of...

what else could I check?
o2 sensor?
I looked for vacuum leaks but did not see any...
i have been searching online for this issue and some say
oil in the distributor 9 did nto see anything there went i put button in)
or a failing MAF ( maybe clean it?)


not sure where to go next...