Wats up RX8Club I read some posts about some ppl cleaning their throttle bodies, so I figured Id do it too. So I took off the TB, and cleaned it. First I took a brillo pad to it to clean up some of the grime that was gunked up on the outside. Then I took some TB cleaner and sprayed the living days out of the thing and scuffed it more. It looks awesome but when the car is running the idle is at 1000-1200 RPM. I scanned the ecu and besides the usual o2 sensors coming up, i got code P0507(Idle Air Control System RPM higher than expected) I checked for vacuum leaks but nothings leaking. Everything was hooked up correctly. I even took everything apart and did it again. Anybody know what it could be? PLease any ideas are welcome.

 

Any ideas? I searched the code on the forums and a few threads come up but nothing definite. I checked for vacuum leaks, checked the little hose behind the intake and i cleaned my MAF. Anything else I should be looking for?

 

VDI hose maybe? Definitely sounds like some type of vac leak any other codes? Hoses connected to wrong nipples maybe?

 

Which is the VDI hose and when you mean the hoses connected to different nipples, would it matter cuz all 3 are relatively in the same spot, but nonetheless yes theyre correct. And the only other codes are my 4 oxygen sensor codes. But which is the VDI hose?


::EDIT:: My idle has dropped a bit. Its sitting at 1000 RPM flat.

 

A P0507 DTC trouble code may be caused by one or more of the following:

A vacuum leak
Leaking air intake after the throttle body
EGR valve leaking vacuum
A faulty positive crankcase ventilation (PCV) valve
Damaged/failed/dirty throttle body
Failed EVAP system
Failed IAC (idle air controller) or faulty IAC circuit

 

All clamps nice and tight?

 

yea im getting clamps tomorrow just to make sure i have no leaks. also im gonna throw some soapy water on my lines to make sure theres no pin holes. Ummmm it cant be my TB cuz i just cleaned it flawlessly. Ummmm wheres my IAC sensor and EGR? I know what they are but idk where they r on the motor

 

There is no egr and the IAT is located on the Maf

 

It's entirely possible that u have damaged the TB plate stepper motor.
Or knocked it out of whack some.
I know of no way to fix that.

Turning the car to the on position but not running you should be able to see the TB position when the pedal position is off and WOT. See if evrything looks ok.

Its an easy check, at least something to remove as a problem.

 

I def. will check that, I did notice however that the throttle body doesnt close fully when i had it out. I mean it was fractions of an inch from being fully closed but something enough for me to notice. I could push the plate to make it fully closed but could that be the problem? I mean the car idled fine before. It would stay at 810-850 for days. Anybody know if theyre supposed to close fully? I mean if its supposed to close fully, there was a decent amount of gunk where the TB plate and the inside diameter meet. Could it be that ive had this problem before but the gunked up oil was keeping it from being noticed?

 

I'm a nice guy, I searched for you.

....but you won't like the answer -

thread - https://www.rx8club.com/showthread.php?p=4038405

see post #5 by Mazda Maniac.......

You're welcome.

 

His idle is too high. That would tend to suggest the opposite of the link topic you provided.

 

^^^ But if my TB isnt fully closing then wouldnt my idle be high? There was a black "gunk" around the plate on the bore of the TB so i did "clean" it out. My main question is, does the TB completely close on it own, or is there still some room where u can push it closed?

 

The throttle body never fully shuts at idle. If it did (when idling) it would kill the engine. Due to no air. Kinda like a choke.
Now if you messed up the throttle position motor alignment, maybe you would have a high idle issue. Pushing the butterfly fully shut could have misaligned it. And thinking it's in it's programed location at idle, instead, may be open a bit more than prior. Causing high idle.
All in theory.

I'd check for vacuum leaks. I know you said that you did. But.
Did you do anything with the MAF? Clean it? Remove it?

 

No i didnt clean the MAF at first but after I noticed this problem, I sprayed it with MAF cleaner. Also as an update, I did get clamps for all my vacuum hoses but the idle is still high. It has gone down a bit and now rests at 1000-900 RPM after about 20 sec of sitting. As soon as I tap the throttle or get moving the car will idle back at 1200 RPM for again about like 20 sec then go down to around 900 RPM. I even went as far as to re install the factory intake(I had K&N installed) and still no dice. Since it has gone down a bit, Im gonna go ahead and clear the code and see if it comes back. Do you think I should reset the ECU?

 

Do you have a buddy locally that has an RX-8? Has a code reader or Accessport?

If you do swap the TB's and see if it fixes the problem....

If it does you can get a used one easily......if it doesn't you can look somewhere else

If it doesn't get back to us with some data...LT and STFT's and MAF readings would be a help

 

Go ahead and do the ECU reset procedure. Quickly stomp the brake pedal a bunch (with the ignition ON) until the oil pressure needle sweeps right to left.
Take it out for a drive.

 

Contrary to Teams input, if you 'clean' all the soft rubber from the throttle blade seat, air will be rushing in at all times, making a low controllable idle impossible.

You be needin a new TB......

 

Bit off topic but I was wondering about the Cobb access port can you just borrow someone else and do everything you need with it, or can it just program one car. I just think I would rather borrow someone's for a day then buy my own.

 

Hey sweet ..... first of all ... nice hi-jack of the topic with something that doesn't even remotely come close to what the OP was about.

Second .... all you have to do is just the basic amount of searching to figure this out you lazy douche.

Third .... you're a cheap son-of-a-b@#$% go buy one

I will however give you credit for not starting a new thread on the topic.

--- maybe I will ---- I've had it with this place

 

I did mis-read the linked thread so you may be right, thanks for pointing this out

and wcs, welcome to my world

 

That only resets the ESS profile, not the overall PCM data. You will need to either pull the room fuse or disconnect the battery for 15 minutes to reset the PCM.

 

After I posted that I was thinking that ^. lol.

Thanks for pointing that out.