So i turn on my car from a cold start last week and a check engine light immediately pops up and the idle starts going crazy/ pulsating. it sounds like im lightly revving the motor in half second intervals however my foot is not on the pedal. I check the code and it says p1519(idle air control valve circuit failure). The only way i can drive the car is to reset/clear the check engine light so it doesnt rev however upon letting the car cool, the cel comes back on and i'm at square one.

Just to inform you guys, i have no modifications done to the motor. it is a 2001 s2000 with 46,000+ miles.

What I've done: MAP whack with zip tie(as you can see in the video) and thoroughly cleaned the IAC valve.

I'm assuming i need a new IAC. What do you guys think?

1)Cold start(70 degrees outside) Havent driven the car in 2 days.[media]http://www.youtube.com/watch?v=uTPh63N8ouY [/media]&feature=mfu_in_order&list=UL


2)Let the car run for 5 min. then turned it off and turned it back on[media]http://www.youtube.com/watch?v=MNRZn3rfH_w [/media]&feature=mfu_in_order&list=UL


3)motor shot( may or may not be relevant)[media]http://www.youtube.com/watch?v=5W7ZrqQHmlw [/media]&feature=mfu_in_order&list=UL


Thanks for reading/watching. Diagnosis?

 

bad tps?

 

I seem to be having a simular problem as well, though I havent checked what CEL code I have yet.

Mine pulsates too, on cold starts, but doesnt fluctuate as much as yours does. however it is definatly notable by the exhaust tone and the digital needle going up and down.

Do you still get the lumpy idle after driving around for a while (fully warmed up)?

 

IAC, or connector.

If the idle is fluctuating up and down, and no code is present, the valve is sticking and needs to be cleaned.

 

the idle affects my balancing the clutch so i just leave the car. tried driving a half mile to a friends house and couldnt make it.

 

bought a new IAC so i will be installing it when it arrives tomorrow. hopefully its not a connection problem.

Thanks for the responses guys. anyone else?

 

i have the same problem, someone help!

 

please let us know how the problem solves after you install the iac

 

UPDATE:

installed a new iac and all is fine. 150 miles and several start ups with no problems.