First Car, 87 325E

[th3count]

hey guys just got my first car. an 87 325E, have done a few minor fixes to the vehicle since i got it about a month ago(oil change) then a few minor cosmetic things on the interior. now first off i know very little about carsm i've always been a DIY guy and enjoy the thrill of fixing something yourself and the knowledge you gain from it aswell. I don't even know where i would begin to start diagnosing this issue guess thats why im here.

My problem is Cold engine idle sparatic from 850rpm to 1250 rpm, then i beleive this may also be related is 1st, 2nd, and sometimes in 3rd gear holding at about 1500 RPM +/- the car shudders. i want to solve this problem as it doesn't feel good and its probably not good on the car.

SIDE NOTE: Also while car is cold gear shifter is very stiff and sometimes won't go into gear. (this has only started happening over the last week since i had my tranny fluid changed by national transmission) and i coulda sworn i grinded a gear this morning with the clutch fully depressed to the floor. (clutch usually grabs near full release of the peddle)

colder the engine the longer both of these conditions seem to last. from reading online the only things i can come up with personally are, mass air intake, air flow sensor, or a leaking vacuum hose. any other ideas or insight?

thanks guys.