1988 Mazda 626

My car is ideling rough mainly when in gear and at a stop with my foot on the brake and will idle smoother if I put it in nuteral. Even if it is not in gear the idle is somewhat rough and the RPMs will occasionally drop for a second than back up. With all of this if I roll up the electric windows, the power used on the windows makes the RPMs drop way down and the car idle very rough, it somewhat does it with turning on the lights and blinkers you can see the RPMs drop and idles a little rougher. Now just recently when I go to accelerate at times it is lacking power for a little bit than will clear up. I went to check the air intake and found a whitish milky residue in the air intake hose just after the air collection cannister and some in the throttle body