idle/rpm provlem for my 03 evo 8

im having a problem with my evo when ever it is running at normal temp and im reving bout 2000 rpms or higher and then i relief the tranny of stress either push in the clutch or throw it out of gear the rpms drop to bout 200 rpms then jump up to 1000 then down to 200 and then returns to regular idle at bout 900 then stays there or some times it dies i was wondering what could possibly be making it do this

Sounds like the IAC or MAF is possibly going bad... I would start there with checking them out.

what is a IAC and MAF a guy told me i had to reciculate my blow off valve another told me it could be a vaccum leak or the waste gate stacking

If it was a vacuum leak then it would do it all the time. Not just after getting up to operating temperature. What did he mean by the wastegate was stacking? I've never heard that term used before... The blow off valve not being recirculated could be part of it too. But again, I would think it to do it all the time then.

IAC = Idle air controller - This controls your idle once you reach normal operating temperature to keep it from stalling out. If you notice, when you start a car and it is cold, it will usually run at a slightly higher RPM as a factory loop mode default from the ECU. Once it reaches normal operating temperature then the IAC takes over this function... I'm pretty sure I explained that right, but I could be off a little. It's been a while since I've had to explain things.

MAF = Mass Airflow Sensor - This measures the amount of air being drawn into the turbo and eventually in turn into the motor. If the MAF doesn't know how much air is going into the motor then the ECU doesn't know how much fuel to give it, which can cause iradic idle...

As you can see, either of these two devices can cause your problem... But... Being an Evo, they could be running a different setup than I am used to on older DSM's... Do you have a check engine light on with the problem? If so, you could have someplace check it and get the engine problem code from it and then you'll know exactly what to replace/check. Gotta love newer technology. lol

ya i though bout what hte iac and maf was i was just having a brain fart but when my car is cold it does rev higher then usual until it worms up so i dont think its the iac but is there any way to test the maf or it somthing that i would have to replace before i could find out if that is the problem

ya i though bout what hte iac and maf was i was just having a brain fart but when my car is cold it does rev higher then usual until it worms up so i dont think its the iac but is there any way to test the maf or it somthing that i would have to replace before i could find out if that is the problem
Hmmm... I'm not sure of a definite way to test them, but here is one possible way...

Let the car sit idling until it starts jumping around with the idle on its own. While it is doing that, pop the hood and unplug the maf from the harness. If it doesn't get worse or change, then that is a problem. If it gets worse or stalls out though, then the maf is NOT the problem.

Maybe you should get a Haynes manual for it and it will have better troubleshooting tips and ways to test things for the EVO. I'm sure it's all quite a bit different than the earlier 4g63 motor setups.

ya i took it to a shop and they found out that the guy that i bought the car off of and he had put in a greddy after market waste gate cyliniod and unplugged the old one well the after market one is pressuried the factory one was electronic and didnt plug anything in where the factory one so now there nothing filling the spot of the cyliniod so all i have to do is find something to plug in there to trick the comp. in thinking there is a cyliniod there

Wait... You lost me... He what? Wastegate selonoid? You mean the wastegate actuator? That should be run off of a vacuum line. It's a mechanical part... Are you sure the shop even knew what they were talking about?