IDLE PROBLEM AM HAVING PROBLEMS WITH MY IDLEING ON MY CAR. CHANGED IDLE SENSOR STILL DOING THE SAME THING. SOME PEOPLE TOLD ME TO CHANGE THROTTLE BODY. WHEN THE CAR WARMS ON IT DROPS FROM 4K RPM TO 2K RPMS BUT THAT IS STILL HIGH. ANY BODY HAVE ANY SOLUTIONS 1990 CIVIC SI ENGINE (ZC VTEC SINGLE CAM)

Do you have any trouble codes?

check for vacuum leaks!

Tanya
why no symptoms stated?, or DTCs (so we can be on the same page?)
the car has and FSM that covers all this.
or alldata.com
there is no idle sensor.
there are many sensors but idle is not one of them.
the Engine runs and will not run with bad cam and crank sensors
these 2 sensor, derive , RPM. and idle speed, is adjusted all the time
based on those 2 sensors
then the PCM controls idle via the ISC< the idle speed control valve.
its a valve. it controls idle air supply.
my guess is the engine stalls.
or races fast and has lack of power.
and the CEL lamp in the dash glows and is screaming for you to scan the PCM? right? and you did not?
if you did it will have DTCs warning you of idle related failures.
pure.
or as any mech knows, idle is the LAST thing to work right.
if the engine runs bad, idle can fail.
the ecu controls idle at all times, if it can't we do test to find out which is it?
On newer cars, there are up to 4 (count them) 4 TPS sensors.
2 on the right foot throttle and 2 in the throttle body.
if any of the 4 dont agree, the CEL glows and the DTC get stored.
telling you that this Happened, not looking and scanning the PCM
you miss all those facts.
in most new cars if that happens the PCM goes to limphome mode
so engine power is greatly limited, after all the idle is out of control
and no car maker wants to be TOYOTA (read the news)

how to , is covered in the FSM, buy one,
and at alldata.com
in some cases it takes a dealer TOOL to re-learn the idle controls.
that fact is there too.

and warning 2, some TPS can not be changed,
you must buy a whole new throttle body.
other cars, like, my new jeep its a new idle; and throttle motor.

You car has throttle by wire, you need to learn how this works first.
then fix the car.

My guess would be the mass air flow sensor, but unfortunately there's

had the same problem with the same year model, changed the idle position sensor, did not fix problem. took it to dealer because I was told that it had to have an idle relearn program ran on it, it didn't take and the dealer toldme that I need a ECM (engine control module) basically a new computer and it would cost with labor about 1100.00 dollars.

You can manually test the egr valve by pushing up from underneath it and seeing if the spring loaded valve moves and re seats itself. If no, it's bad.

should be ok because a thing called a zena diode in the alternator should have protected the alternator

P2176=Throttle Actuator Control System - Idle Position Not Learned
Did you use all you old sensors,or is some of them from the new engine,I would swap out the IAC sensor or check for wires not hooked up.
If it can't relearn to idle the Idle air control might be different then your old one,but its not registering with the computer

I did not have the light dimming thing but I had the same problem with the idle... frustrating.

I picked up a repair manual at the parts store. I took off the throttle body and cleaned it with throttle body cleaner spray. I changed the Idle Air Control Valve (idle speed motor) which was very clogged. While I had the throttle body off I also changed the Map Sensor and Throttle Position Sensor. The manual will walk you through the steps. I had never done anything like this before. If I can do you so can you.
My Jeep has never run better. Good Luck

I replaced the Cam Shaft Sensor. I also cleaned the Throttle Body with carb cleaner. I had my wife hold down the accelerator, while running I sprayed down the throttle plate and the entire area around it. Now my TB finally idles smoothly, and it hasn't died yet!! Check engine light is gone and I passed the emissions test!! Yea!!!

Still sounds like a vacuum leak or Idle air control valve sticking open. May want to recheck the tps sensor because sometimes they can be put on wrong and hang the throttle open. I you still have questions please ask. Hope this helps.