Survey by Qualaroo
+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 20 of 28
Like Tree2Likes

Thread: AC Idle up issue - 1NZ-FE

  1. #1
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default AC Idle up issue - 1NZ-FE

    Assalamulaikum all.
    I need some help with an issue that I've been facing for some time now. The car in question is an 03 Corolla that has a 1nz-fe swapped into it. Now the issue is that with the AC turned on, the idle speed does not increase as it should. Neither does it increase when the steering wheel has been turned to maximum or when depressing the brake pedal at idle. I've tried 3 different throttle bodies with the same results.

    However, at cold start, the idle goes up perfectly the way it should. I've taken apart an idle control valve from one of the throttle bodies and connected it stand alone with the icav connector to see if it moves with the ac on, it doesnt.

    I've checked the continuity at all three wires of the connector and its fine. The middle one gets +B, the left one ground, and the right one signal from the ecu.

    I've got a 2nz-fe in my charade and I've compared the voltages with it. At idle, it has the same voltages as the 1nz but when the brake pedal is pressed or the steering is turned to the maximum, the voltage on the third pin in the icav connector (the one controlled by the ecu) drops from around 6.9v to 6.2v and the idle goes up the way it should whereas, in the corolla, it stays at 6.7v without an increase in the idle.

    I'm attaching a couple of videos to show you what I mean. The first one is of the charade and the second one of the corolla. The second video will also show the difference with the AC running towards the end.

    Any insight on this issue would be highly appreciated. Thanks.
    @Xulfiqar and @SER_GTR Please help me out here. Thanks.





  2. #2
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default


  3. #3
    Senior PakWheeler Follow
    SER_GTR's Avatar
    Join Date
    Nov 2005
    Location
    Karachi
    Age
    30
    Posts
    9,734
    Follows
    16
    Following
    0
    Mentioned
    488 Post(s)
    Tagged
    19 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    3

    Default

    A/C Is COnnect Via ECU???? If NO Then It Will Not Work As You Wish....Its Should Go Via ECU Or Known ECU That Compressor Is Engaged In Order To Raise Idle...!!

    There Are Certain Pins On ECU In A Series E Series ECU's Which Are Powered To Let ECU Know As Load Goes Connected...ANd They Raise RPM.....
    TOYOTA Sprinter 86- AE80 DOHC 20v'D TOYOTA Corolla 98- AE101 4AFE 16v

  4. #4
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    @SER_GTR Yes, the ac is connected through the ecu. The ac connection is infact stock as it came from the factory.

    In the older generation engines, A and E series, there were load signals given to the ecu like ELS which would increase the idle, the same is even true for the newer ones driven on CAN, in this engine however, there is no such thing and the load is detected by the ecu itself somehow.

    Sent from my HTC One S using PW Forums mobile app

  5. #5
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by Owais_Yunus View Post
    @SER_GTR Yes, the ac is connected through the ecu. The ac connection is infact stock as it came from the factory. This issue started back when it had the 2nz-fe in it and its still there.

    In the older generation engines, A and E series, there were load signals given to the ecu like ELS which would increase the idle, the same is even true for the newer ones driven on CAN, in this engine however, there is no such thing and the load is detected by the ecu itself somehow.

    Sent from my HTC One S using PW Forums mobile app


    Sent from my HTC One S using PW Forums mobile app

  6. #6
    Senior PakWheeler Follow
    umarkhan1's Avatar
    Join Date
    Nov 2010
    Location
    Sargodha
    Posts
    2,306
    Follows
    6
    Following
    8
    Mentioned
    51 Post(s)
    Tagged
    4 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    2

    Default

    Have you adjusted the variable resistor type thingy???


    Sent from my iPhone using PW Forums
    Just Do It Your Self!!!!!

  7. #7
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by umarkhan1 View Post
    Have you adjusted the variable resistor type thingy???


    Sent from my iPhone using PW Forums
    Are you talking about the idle control valve or the variable resistor issue that I previously had with charade's 2nz?

    Sent from my HTC One S using PW Forums mobile app

  8. #8
    PakWheeler Follow
    NiGhTShAdE's Avatar
    Join Date
    Nov 2011
    Location
    Lahore
    Age
    29
    Posts
    917
    Follows
    1
    Following
    1
    Mentioned
    62 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Does a/c and power steering work correctly? if yes then secondly does rpm stays constant or do they drop below 750?
    If both things are working correctly and rpm stays constant then everything is fine....ideally rpm should not increase ...when a/c or power steering operates ECU sends a signal that load has been applied on the engine and maintains rpm via operataing IACV when car is idling..... in brand new and perfect engines there is absolutely no change in rpm when load is applied....only rpms should not fall....if they do then there is a problem....
    NiGhT ShAdE>>~

  9. #9
    Senior PakWheeler Follow
    SER_GTR's Avatar
    Join Date
    Nov 2005
    Location
    Karachi
    Age
    30
    Posts
    9,734
    Follows
    16
    Following
    0
    Mentioned
    488 Post(s)
    Tagged
    19 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    3

    Default

    If Its Connected The ECU Is Responsible For It....!

    In 4AFE There's Adjustable Type IDle Valve Used Which Raise RPM And You Can Also Adjust It.....Try That If ECU Is Not Responding..

    Either Connections Are Not As You Said Or ECU Gone Bonkers On That...
    TOYOTA Sprinter 86- AE80 DOHC 20v'D TOYOTA Corolla 98- AE101 4AFE 16v

  10. #10
    Senior PakWheeler Follow
    SER_GTR's Avatar
    Join Date
    Nov 2005
    Location
    Karachi
    Age
    30
    Posts
    9,734
    Follows
    16
    Following
    0
    Mentioned
    488 Post(s)
    Tagged
    19 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    3

    Default

    Or MAybe Any Part Of It Is Missing...Take Help From Service Manual And See If You Have All The Parts Available For A/C Connections...
    TOYOTA Sprinter 86- AE80 DOHC 20v'D TOYOTA Corolla 98- AE101 4AFE 16v

  11. #11
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by NiGhTShAdE View Post
    Does a/c and power steering work correctly? if yes then secondly does rpm stays constant or do they drop below 750?
    If both things are working correctly and rpm stays constant then everything is fine....ideally rpm should not increase ...when a/c or power steering operates ECU sends a signal that load has been applied on the engine and maintains rpm via operataing IACV when car is idling..... in brand new and perfect engines there is absolutely no change in rpm when load is applied....only rpms should not fall....if they do then there is a problem....
    Yes, both the ac and the power steering are working fine. The ac should send a signal to the icav to increase the rpm and so should the pressure sensor in the power steering pump but the issue is that the rpms do not stay maintained under the use of these two things and it drops a couple of hundred rpms which is annoying me. It was fine around 30-40k km back when the car had a 2nz-fe in it but after that, I started to face this issue. Around 20k km back, I swapped the engine to a 1nz-fe and this issue still wasnt rectified but it didnt bother me because it was the winters and airconditioning wasnt used. Ever since the start of the summers, this issue has come back to haunt me.

    Sent from my HTC One S using PW Forums mobile app

  12. #12
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by SER_GTR View Post
    If Its Connected The ECU Is Responsible For It....!

    In 4AFE There's Adjustable Type IDle Valve Used Which Raise RPM And You Can Also Adjust It.....Try That If ECU Is Not Responding..

    Either Connections Are Not As You Said Or ECU Gone Bonkers On That...
    The idle can manually be adjusted by rotating the icav but that means that I have to keep the idle at around 1.1k rpm without the ac running so that it maintains the rpm at around 800 when the ac is turned on. That is what I want to rectify, I want the idle to be automatically maintained like it should. And about the connections, I've checked and rechecked over and over. I have two ecus for the 1nz-fe and the issue remains with both the ecus. Infact, like I said, it was there when it had the 2nz so that ecu was also tested for this which is now working fine in the charade.

    Sent from my HTC One S using PW Forums mobile app

  13. #13
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by SER_GTR View Post
    Or MAybe Any Part Of It Is Missing...Take Help From Service Manual And See If You Have All The Parts Available For A/C Connections...
    I've checked for missing parts and there arent any. I have 1nz's manual. The car has been with us ever since it was new and I got the swap done myself and the electricals have not been touched by any ustaad so they are all there. Now one could point towards the ac controller being faulty but that does not have anything to do with the idle increasing with the steering being turned to the maximum or the brake pedal being depressed at idle which too are not working. So it seems to be related to the icav somehow, how, that I'm not sure of.

    Sent from my HTC One S using PW Forums mobile app

  14. #14
    Senior PakWheeler Follow
    umarkhan1's Avatar
    Join Date
    Nov 2010
    Location
    Sargodha
    Posts
    2,306
    Follows
    6
    Following
    8
    Mentioned
    51 Post(s)
    Tagged
    4 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    2

    Default

    Quote Originally Posted by Owais_Yunus View Post
    Are you talking about the idle control valve or the variable resistor issue that I previously had with charade's 2nz?

    Sent from my HTC One S using PW Forums mobile app
    yes the resistor that you were having in your charades.not sure but it can be a problem.
    Just Do It Your Self!!!!!

  15. #15
    Senior PakWheeler Follow
    SER_GTR's Avatar
    Join Date
    Nov 2005
    Location
    Karachi
    Age
    30
    Posts
    9,734
    Follows
    16
    Following
    0
    Mentioned
    488 Post(s)
    Tagged
    19 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    3

    Default

    Quote Originally Posted by Owais_Yunus View Post
    The idle can manually be adjusted by rotating the icav but that means that I have to keep the idle at around 1.1k rpm without the ac running so that it maintains the rpm at around 800 when the ac is turned on. That is what I want to rectify, I want the idle to be automatically maintained like it should. And about the connections, I've checked and rechecked over and over. I have two ecus for the 1nz-fe and the issue remains with both the ecus. Infact, like I said, it was there when it had the 2nz so that ecu was also tested for this which is now working fine in the charade.

    Sent from my HTC One S using PW Forums mobile app
    That Thing Only Adjust Idle's At A/C.......It Works When A/C Kicks Inn..Sort Of Vacuum Valve Adjustable......

    For ISCV .....It Get Voltage Readings From ECU And Act Accordingly...If Its Working All Fine.....Not Jamn'ed Or Anything....Its Working Fine...!
    TOYOTA Sprinter 86- AE80 DOHC 20v'D TOYOTA Corolla 98- AE101 4AFE 16v

  16. #16
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by umarkhan1 View Post
    yes the resistor that you were having in your charades.not sure but it can be a problem.
    That resistor adjusts the air fuel mixture and that has been taken care of. This engine has an O2 sensor instead of that resistor. That is however not related to the idle issue that I have in the corolla.

  17. #17
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by SER_GTR View Post
    That Thing Only Adjust Idle's At A/C.......It Works When A/C Kicks Inn..Sort Of Vacuum Valve Adjustable......

    For ISCV .....It Get Voltage Readings From ECU And Act Accordingly...If Its Working All Fine.....Not Jamn'ed Or Anything....Its Working Fine...!
    Oh that vacuum switching valve. No, this engine does not have that valve and its idle cannot be controlled with such a valve. About the voltages, I've compared them to the charade which here is a properly functioning specimen and they both have the same voltages on two of the terminals except the third one about which I've posted the two videos above. The third terminal on the charade stays at 6.9v while idling and drops to 6.2v when load is applied which simultaneously increases the idle and stays at 6.2v until the load is taken off. In the corolla, the voltage does not drop to 6.2v under load and that is probably whats wrong with it. Why that is happening, is what needs to be figured out since the connectivity in all the wires is fine. What could cause such an issue is what I'm on about. And the idle valve is not jammed either. Its smooth as butter.

  18. #18
    PakWheeler Follow
    NiGhTShAdE's Avatar
    Join Date
    Nov 2011
    Location
    Lahore
    Age
    29
    Posts
    917
    Follows
    1
    Following
    1
    Mentioned
    62 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    As you said cold start idle goes up mean IAcV is working properly...its just that is not getting signal to 'maintain' rpm on ac and power steerig.... so assume Iacv is fine....btw is MAP sensor correctly wired and properly working?

    Sent from LG Optimus LTE LU-6200 using PW forums mobile app
    NiGhT ShAdE>>~

  19. #19
    PakWheeler Follow
    NiGhTShAdE's Avatar
    Join Date
    Nov 2011
    Location
    Lahore
    Age
    29
    Posts
    917
    Follows
    1
    Following
    1
    Mentioned
    62 Post(s)
    Tagged
    0 Thread(s)
    Problems Posted
    0
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    map sensor also plays a vital role in maintaining rpm...and is the only thing other than ecu linked with all load variation....simultaneously

    Sent from LG Optimus LTE LU-6200 using PW forums mobile app
    NiGhT ShAdE>>~

  20. #20
    Senior PakWheeler Follow
    Owais_Yunus's Avatar
    Join Date
    Sep 2005
    Location
    Islamabad
    Age
    28
    Posts
    2,224
    Follows
    4
    Following
    0
    Mentioned
    60 Post(s)
    Tagged
    1 Thread(s)
    Problems Posted
    1
    Problems Solved
    0
    Best Answers
    0
    Good Answers
    0

    Default

    Quote Originally Posted by NiGhTShAdE View Post
    As you said cold start idle goes up mean IAcV is working properly...its just that is not getting signal to 'maintain' rpm on ac and power steerig.... so assume Iacv is fine....btw is MAP sensor correctly wired and properly working?

    Sent from LG Optimus LTE LU-6200 using PW forums mobile app
    Thats what has me perplexed aswell. If its working fine on cold idle then whats the issue :s this engine has a MAF sensor which is totally fine and not generating any trouble codes. Other than this issue, the car is running fine alhamdulillah. If the maf is faulty, it normally greatly affects the performance and fuel economy, both of which are top notch alhamdulillah.

    Sent from my HTC One S using PW Forums mobile app

+ Reply to Thread
Page 1 of 2 12 LastLast

User Tag List

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •