Results 1 to 20 of 20

Thread: rough idling

  1. #1
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    rough idling

    hello guys, its been a while since the last time i'm at this site... need a little help from the TVT pros with my van. In park or neutral gear, idles fine but when put into drive, idling becomes rough... what are the things to check?

  2. #2
    Van Fan
    My Van(s):
    1984 Toyota Van (Don't have anymore) Replacement: 2008 Chevy Cobalt LT (Also don't have anymore) Current Car: 2021 Subaru Legacy Premium
    Join Date
    Sep 2010
    Location
    Skamokawa, WA
    Posts
    65
    Rep Power
    1

    Re: rough idling

    Check the air intake hose right at the throttle body. I think you got a hole. Most likely at that first "rib." Easy fix. Use a rubber cement, like GOOP, and wrap it several times with electrical tape.

  3. #3
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    thanks for the reply sir. i'll go check it out. i'll update the outcome

  4. #4
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    checked all air and vaccum hoses, no leaking found. what else could be the problem? any suggestions TVT's?

  5. #5
    Van Fan
    My Van(s):
    1984 Toyota Van (Don't have anymore) Replacement: 2008 Chevy Cobalt LT (Also don't have anymore) Current Car: 2021 Subaru Legacy Premium
    Join Date
    Sep 2010
    Location
    Skamokawa, WA
    Posts
    65
    Rep Power
    1

    Re: rough idling

    Does it cough or sputter when you try to get going?

  6. #6
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    no, van doesn't sputter nor cough. as you accelerate the rough idling fades away and then as you stop while still at drive gear, idling rough again. what do you think sir? what and where should i check?

  7. #7
    Van Fan
    My Van(s):
    1984 Toyota Van (Don't have anymore) Replacement: 2008 Chevy Cobalt LT (Also don't have anymore) Current Car: 2021 Subaru Legacy Premium
    Join Date
    Sep 2010
    Location
    Skamokawa, WA
    Posts
    65
    Rep Power
    1

    Re: rough idling

    Is it running like my Van is in this video? A bad lifter can cause a misfire but run totally fine on the highway.


  8. #8
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    thank you very much sir for that video but no, van doesn't run like that, as long its in nuetral or park, idles fine as soon as you put gear into drive, idling becomes rough. the engine still runs quiet, i don't have that "clang clung" (diesel-like) sound that i'm hearing from your video. any more ideas sir?

  9. #9
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,202
    Rep Power
    10

    Re: rough idling

    I agree with KC's 1st suggestion. It's really easy to miss a torn intake hose. Another way to check is to squeeze the hose while idling in neutral. If it's a bad hose squeezing it will cause the crack will open bigger & it will stumble or stall. The reason it runs bad while in gear is because the motor torques to one side causing the crack to open bigger. My money is on a cracked/torn intake hose. Tim

  10. #10
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    thank you sir tim. i'll try to thoroughly check again that hose. i'll update as soon as i'm finished checking

  11. #11
    Van Fan RawbSpear's Avatar
    My Van(s):
    87 4wd automatic
    Join Date
    Sep 2010
    Location
    Marin CA
    Posts
    40
    Rep Power
    1

    Re: rough idling

    cold, warm, hot, or all 3?
    At the sirens of humanity we STOMP!

  12. #12
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    after a thorough check of the big hose, no cracks found at any part of it. i did the squeeze test that you told me sir tim , the idling stayed fine only rpm drop happened. Hi sir RawbSpear, good question, the rough idling starts to soften when the engine is warm to hot or after a long drive. any more ideas sir?

  13. #13
    Van Fan RawbSpear's Avatar
    My Van(s):
    87 4wd automatic
    Join Date
    Sep 2010
    Location
    Marin CA
    Posts
    40
    Rep Power
    1

    Re: rough idling

    Idle up temperature switch, and cold start timing switch. Posible temperature switch issue.

    you said you experienced a change in idle when you squeezed the hose from the M.A.S. and the throttle body? That means there was a change that the computer tried to compensate for. ~~Triple, quadruple check the hose with a magnifying glass. NO LEAKS ARE ACCEPTABLE FROM M.A.S. (M.A.F.S.) TO THROTTLE BODY!

    Have you checked the numbers coming from your M.A.S? are they correct? E.F.I. is the first problem in the fuel system.

    @KCG: park your van till you have lots of money. Making me sad after i watched your video.
    Attached Images Attached Images  
    Last edited by RawbSpear; 09-08-2012 at 12:02 AM.
    At the sirens of humanity we STOMP!

  14. #14
    Van Fan
    My Van(s):
    1984 Toyota Van (Don't have anymore) Replacement: 2008 Chevy Cobalt LT (Also don't have anymore) Current Car: 2021 Subaru Legacy Premium
    Join Date
    Sep 2010
    Location
    Skamokawa, WA
    Posts
    65
    Rep Power
    1

    Re: rough idling

    Quote Originally Posted by RawbSpear View Post
    @KCG: park your van till you have lots of money. Making me sad after i watched your video.
    I replaced the bad lifter a long time ago. It runs very well now. I haven't been driving it now because it's not licensed, needs a new battery, and the back door latch is broken.

  15. #15
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    guys sorry for the late response, i've checked the three sensors on the rad, following the steps on the manaul, they are in good condition. what could else be the problem? as of now, the rough idling is still there though sometimes its fine. any more ideas what to other things to be checked? i'm really having a hard time making time for my van because i'm busy preparing for my wedding, we also plan to make van our wedding car.... thanks a lot guys... hoping for your help

  16. #16
    Van Fan RawbSpear's Avatar
    My Van(s):
    87 4wd automatic
    Join Date
    Sep 2010
    Location
    Marin CA
    Posts
    40
    Rep Power
    1

    Re: rough idling

    you have good plugs, wires, cap and rotor right? good o2 sensor? clean air filter?
    At the sirens of humanity we STOMP!

  17. #17
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    yes i have good plugs, wires, cap and rotor. good O2 sensors. clean air filter. i don't have any codes recorded at ecu. what else sir?

  18. #18
    Van Fan RawbSpear's Avatar
    My Van(s):
    87 4wd automatic
    Join Date
    Sep 2010
    Location
    Marin CA
    Posts
    40
    Rep Power
    1

    Re: rough idling

    have you pulled off the throttle body and cleaned it?
    checked all the numbers of the MAS?
    good ground, strong battery?

    the next step is testing fuel injectors and the air sensor. Top of motor comes off to get to all that. Look in the FI section of the manual and you will know what i am talking about.
    At the sirens of humanity we STOMP!

  19. #19
    Van Fan davidgracevan's Avatar
    My Van(s):
    1989 Toyota Van LE 2WD A/T
    Join Date
    Nov 2011
    Location
    Philippines
    Posts
    53
    Rep Power
    1

    Re: rough idling

    ok i will check all of that... thank you very much... i'll update as soon as i have my time again

  20. #20
    Van Fan RawbSpear's Avatar
    My Van(s):
    87 4wd automatic
    Join Date
    Sep 2010
    Location
    Marin CA
    Posts
    40
    Rep Power
    1

    Re: rough idling

    make sure to have a new throttle body gasket on hand for when you re-install it after cleaning.

    while you have the throttle body off check the numbers on the T.P.S.(throttle position sensor). its pretty much guaranteed that this part is broken at 150k miles and needs to be replaced. Some of the pro's here say just to replace it if you have not already.
    At the sirens of humanity we STOMP!

Tags for this Thread

Posting Permissions

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