90mustang325hp

just recently my 1990 mustang gt as soon as i would push in the clutch the idle would jump from normal 1100 to about 2800 and hold it self there as soon as i let the clutch out or put it in neutral it would go back down. i took it home and as soon as i unplugged the maf it would go down to 1100 then when i plugged it back in it would go up again? i left it plugged in disconnected the battery and then reconnected it reset the idle and it idled fine. now it is running extremly rich i mean pouring oil out the pipes almost and it sounds like it is missing in one cylinder. i don't understand how this is possible. i am very perplexed any help would be apprecaited i don't know what to do.

thank you,
Aaron

mjr46

run a koer test and make sure there are no IAC codes