Guys PLEASE HELP!! I have a 2000 Honda Civic Hatch with a D16Y7 motor. The car is giving me code P0505(Idle Air Control Valve). I changed the valve and it is still doing the same thing. Idling at 1600Rpm and sputters between 1600-1900 Rpm. Any ideas what to do or how I can fix this. Please help! No idea what else it can be.
Thank you.

 

Did you check for vacuum and intake air leaks?

Does the engine keep running if you cover the top of the throttle body with the palm of your hand?

 

vac leaks do this. specifically, i have seen a bad brake booster cause the same code. if you can't find a vac leak anywhere (spray carb cleaner around vac connections, check for change in idle), clamp the large vac hose that goes into the booster. if the idle normals out, theres your problem.

 

Pull the intake, cover the throttle body and see what happens...
Stays running you have a vac leak.

 

Thank you guys for the responses. Just took off the intake and put my palm there and the car shuts off. So put it back on. Then tried clamping the brake booster and it continues to do the same thing. Any more ideas?

 

check coolant level?

 

Use your finger to cover the hole inside the TB leading to the IACV. Does the idle speed drop?

 

am i missing something here? in order for this theory to work you would have to block off AFTER the IACV hole. if you put your hand on the throttle body inlet you are still blocking the IACV inlet hole

plus, isn't the butterfly valve already blocking everything except what goes thru the IACV?

at least for the 3 wire throttle body mounted IACV. i am not sure if the 2 wire one that goes on the back of the intake manifold is different. but i'd imagine it is still sucking thru the air filter so it prolly makes no difference if 2 or 3 wire

edit: oh wait, you're wondering if the engine is going to die if you cover the throttle body. because it's suppose to if there aren't any vacuum leaks. for a minute i thought you were implying the engine would survive off of just the IACV if you were to block off the throttle body. okay that's enough H-T for today. i should prolly go to sleep but FML

 

Cover the throttle body.

Car stays running= Vacuum leak
Car dies= No vacuum leak.