on my 84 ae the maf went bad about 2 weeks ago, idles like crap and doesnt want to go. so i got a maf from a friend wit a 85 2+2 auto with no prolbems and put it on my car, it idles great but wont go past 2000 rpm (acts like theres not even one there). plug back in the oringal and runs like crap again. tried disconnecting the battery, turning off and on the key, no luck. anyone kno y its doing this?