its a 89 prelude si and it idles fine when i start it but when im driving and i put it in neutral to stop it will stall out if i dont keep giving it some gas. what chould be causing this problem?

 

have you ever cleaned out your intake. ithappened with my 1990 prelude.2.0 si
it was idling rough and sometimes even stall.if im not wrongyoure running a b20a5.
get fuel injection cleaner . disconnect your intake and spray it into your plenum.keep the engine from stalling since the cleaner is gonna make it wanna stall.use the whole bottle if you can.use a second bottle if it works but needs more cleaning.the second thing i can think of is your aib.but try the cheap way first.