Rep Power: 0

OK i searched for some time looking for some kind of help but nothing is coming close. I have a CEL for a p1509= Idle Air Control Circuit Failure. Is this just as simple as a new IAC. The big problem which i think is being caused by this is when I try to hold 2k rmp my engine does this stuttering that almost sound similar to hitting the rev limiter but at 2k rpm. It does it at any speed in any gear at any temp. Its affecting my driving alot. When in fifth gear going fourty (which is a very common speed for me on most roads i drive) the rpm's are at 2k which is when the bucking and stuttering start. I have tried a new(used) IAC valve but no luck. Another symptom i have noticed is at any time before 2k rpm the throttle is smooth but after 2k rpm the throttle gets touchy and i can't really hold any rpm after 2k. Higher rpm's don't stutter too bad. If i get the chance to upload a vid of it i will cause its difficult to explain. Any help is appreciated.

 
Rep Power: 812

get a whole new throttle body assembly off ebay for maybe $50, make sure its for your type of trans auto or manual. put that in, with new gaskets, and do the idle learn.

 
Rep Power: 0

my s13 does the same thing at 2500rpm if the maf is plugged or faulty.
Check all the wires to the sensors, also remove the intake pipe and carefully check for any cracks.

 
Rep Power: 0

ok got a new throttle body, installed it, did the idle learn and it still does the same thing. i even put a different IAC valve on. I dont know what to do now how and what would I check for vac leaks and what else could i check. Im starting to think its the ECU any.

 
Rep Power: 267

Yeah but shouldn't he check wire that plugs into IAC valve? It could be defective.