Return to idle problem D16A6

farfetchedfarfetched Wagonist
in Engine & Drivetrain
Hi all!
I need your guys input on this matter!
I got this wier a$$ problem. When engine is cold it returns to idle after acceleration just fine, or should I say it drops proper amount RPMs to have a smooth shift. However, when engine warms up I get this intermitten slow(reluctant) RPM drop between shifts.
History: 180K miles, new T-belt, W/P, full tune up and full fluid exchange when I got it!
I suspect IAC ... maybe MAP is a bit slow?
I am too lazy to get my Fluke and Mighty VAC to propely diag MAP.
What do you guys think of it?
Cheers!

Comments

  • alupso1alupso1 Wagonist
    Did you replace the O2 sensor? My wagon has the same problem and I'm going to try and swap out the O2 sensor from my other car into the wagon and see if it makes a difference.
  • akiraboyakiraboy HondaCivicWagon.com Founder
    imo its the iacv
  • HaydzHaydz Moderator
    Naw ICAV will be cold idle issues, sounds like FITV.
  • jpciiijpciii familEE
    I have the exact same problem with mine since I did a mpfi swap.

    what is FITV?
  • HaydzHaydz Moderator
    Fast Idle Thermal Valve i believe. Depending on the motor they are located in different places but usually below the throttle body.
  • farfetchedfarfetched Wagonist
    Pacifier wrote:
    Fast Idle Thermal Valve i believe. Depending on the motor they are located in different places but usually below the throttle body.
    The fast idle control solenoid valve, mounted on the right side of the throttle body, is used to increase the air flow rate for fast idling at extremely low ambient temperatures.

    OPERATING CONDITIONS:
    The Fast Idle Control Solenoid Valve is turned on when the Coolant Temperature is Below 14°F (-10°C) AND Engine Speed is Below 1,800 rpm.
    This this form ALLDATA
    Cheers!
  • farfetchedfarfetched Wagonist
    I set the IDLE incorrectly. I have to re-adjust it!
    Start the engine and let it warm up to operating temperature (the cooling fan comes on).
    Connect a tachometer.
    Disconnect the 2P connector from the Electronic Air Control Valve (EACV ).
    Check the idle speed in the no load condition in which the headlights, blower fan, rear defogger, cooling fan, and air conditioner are off. Idle speed: (in N or P) 550 ±50 RPM
    Adjust the idle speed by turning the idle adjusting screw. Turn the ignition switch off.
    Reconnect the 2P connector on the EACV, then remove the HAZARD fuse, in the main fuse box, for 10 seconds to reset the ECU.
    Restart and idle the engine in the no load conditions in which the head lights, blower fan, rear defogger, cooling fan, and air conditioner are not operating for one minute, then check the idle speed. Idle speed:(in N or P) USA: 750 ±50 RPM CANADA WAGON: 780 ±50 RPM
    Idle the engine for one minute with the headlights on high beam, rear defogger ON and check idle speed. Idle speed:(in N or P) 780 ±50 RPM
    Idle the engine for one minute with the heater fan on high (right end position) and the air conditioner on, then check the idle speed. Idle speed: (in N or P) 4WD WITH A/T: 810 ±50 RPM 4WD WITH M/T: 830 ±50 RPM
    If idle speed is out of specifications, see Computers and Control Systems for testing of idle control system. Disconnect the tachometer.
    From ALLDATA
    Cheers!
  • HaydzHaydz Moderator
    Having the idle set incorrectly probably wouldn't effect the return to idle, sounds like a possible vacuum leak also. I had a similar issue on my RTi and it turned out to be the valve that sits above the brake booster.
  • farfetchedfarfetched Wagonist
    Pacifier wrote:
    Having the idle set incorrectly probably wouldn't effect the return to idle, sounds like a possible vacuum leak also. I had a similar issue on my RTi and it turned out to be the valve that sits about the brake booster.
    I've adjusted idle, it got a bit better (not as harsh) but still there!
    I will check for leaks again!
    I think it is TB gasket.
    Thanks!
  • awreckawreck Band Wagon
    I know it's a grave post now but did this ever get solved?these are the only search results I can find fir the same problem and I don't know how to fix it. Thanks and sorry for the dead post bring back.
  • udubrx7udubrx7 Senior Wagonist
    Try and unplug the IACV, then start the car and drive it and see if you have the same problem. Check the vacuum line that goes to the little dashpot on the throttle body, and make sure the plunger in the dashpot isn't sticking.
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