messed up idle-any ideas? '91 FB

[Ghettokracker71]

I just bought an eBay CAI......don't flame me for "stupid purchase" or something... ....I pulled apart my intake,and the tubing doesn't fit...but the MAF adapter does,as does the filter and since my filter in the stock airbox was unbelieveably disgusting......I knew I had to change it...so I put it on...and my idle is screwy....when I cold start it...it starts and runs like always..but...I don't understand because i have an inconsistant problem...Often when idling(park,drive and reverse have all had this)...sometimes sitting for a while,others just stopping at a light or the car has just warmed up...the idle will drop to about 500RPM's and violently dip into 350-ish range and jump back to 500 and systematically repeat...making a slight "bump bump bump" noise,my engine is otherwise 100% stock,...I am about to flip 107k....I know its a minor problem NOW...but I don't want to turn it into a HUGE probem later...Maybe I just need to reset my ECU?