I drive a 2003 rsx with a k20a3 engine. recently, when the engine is at idle and you rev it up to 2000 rpm and let off the the throttle, the revs drop to 500 rpm almost shutting off then it revs back up and settle at 800 rpm. i cleaned the iacv thoroughly and made sure that it moves freely, but the same thing happens.

my mechanic said it was the TPS thats causing it, but when he put the diagnostic machine on im getting .47 at closed throttle and many people say thats in range. I have no CEL. someone please help!!

 

Tps sensor

 

mind explaining why or how? because the manual says .45-.5v is ok!

 

Just is no explaining needed

 

damm

 

http://www.youtube.com/watch?v=jzW9L53B81U


heres a video of the revs.

 

This is taken from ClubRSX forum, google and sign up you'll get more help there.

A: replace the TPS sensor, Its harder than you think because the sensor is not available separatly, whole throttle body needed 650-750. Even if you did get your hands on a new TPS sensor, it is attached by headless screws and would need proper calibration by someone who knows what they are doing, and no the base tb tps sensor wont work as the throttle bodies are reversed between the two.
B: buy a used one- problem being you dont know what your gonna get
C: Buy a spoon Bored out TB for $500 ish, but you wont have cruise control.
D: or any other aftermarket TB (limited and not cheaper)

Now, heres what can happen if you dont fix it. the ECU uses the TPS sensor among a sleuth of others to determine how much fuel it should inject. The TPS sensor, in my case, at idle(reading half open) is running rich, and at wide open throttle(reading 3/4 open) is running very lean, long term this can foul your Cat, and then your stuck with even more money to spend to replace the Cat as well. Why the sensor died, who knows, i tested mine and found it out of spec for various specific measurements. No real explanation was given to me aside from that the sensor is ultra sensative and it can happen from time to time....
there is no other choice other than to simply replace it. Rewiring wont work either.

 

A. i replaced the throttle body. SAME PROBLEM.
b. i replaced the new throttle body. Same Problem.
c. the old tps sensor was reading .47 closed and 4.5 open.

and oh...i am a member of club rsx. they are many member with the same problem thats unsolved.

 

could be a vaccum leak somewhere...i have an issue where my karcepts adapter for the rbc has stripped screws and i get an odd idle all the time...imma take it off this friday and re-tap the adapter to see if that fixes it...so you can get odd idle from having a vaccum leak, i would look for that....

 

a vacuum leak world make it surge when its idling....it doesn't do that,it just go down to 500 rpm then up to 800 when its revved, as the video shows

 

not necessarily, are you on stock manifold?

 

yes im on stock k20a3 manifold

 

stock tb? did you check spark plugs? gaskets for tb an manifold?

 

yes. and it cant be a vacuum leak.

 

Hmm....I had the same thing happen, and it was the IACV. Since you already cleaned it, did you check the seal on it to make sure there are no cracks, tears, etc?

 

Im on clubrsx as well and from all the info i collected this is normal.
No need to worry about it, unless the car completely shuts off then don't worry about it.

 

man come on...its not normal......it just started to happen. i just checked my serpentine belt tensioner and it wobbling back and forth.

 

do you have kpro for your base? The make base kpro don't they?!

Also what are your mods? Do you have a lightened flywheel? Because my car does that.

 

your shift key is stuck. release it and you will be able to stop shouting.

 

no kpro, no lighten flywheel

 

still sounds like vacuum leak to me if you have tried everything we have suggested, take it to the dealership if your convinced something is wrong...apparently nothing we have suggested is helping you or you have already tried it already...
try this....if it doesnt work, see my above post

 

found the problem.......its the o2 sensor