Results 1 to 9 of 9

Thread: RT/TT Rough Idle

  1. #1
    Drives a UFO Feedback Score 0 ilian51378's Avatar
    Join Date
    Sep 2010
    Owner Since
    2003

    Location
    Grand Cayman, Cayman Islands
    Posts
    160
    Thanks
    0
    Thanked 5 Times in 4 Posts

    RT/TT Rough Idle

    Hey guys,

    I have a friend whose RT/TT idles rough and he can't find why that is happening. When idling, the car is shaking and so on. When he hits the gas and goes over 2000 RPM, the issue goes away... He has taken the car to several different shops where they have diagnosed it, but could not find anything wrong with it. His problem is that he lives in Eastern Europe and there are no mechanics that know our cars well enough there... He has replaced the ECU with a rebuilt one that was tested and worked good, but that did not fix the problem. The compression is great and the diagnostics show that everything else is fine. Could it be his air filter (MAS?) sensor? Dirty throttle body? What else could be causing that? Any input is appreciated. Thanks!
    '95 Mitsubishi GTO AWD ATX - '99 front end conversion, TT conversion (15Gs), Paddle shifters, Stealth sails, A/A wing.
    '92 Dodge Stealth ES - 3KGT body conversion. Sold!


  2. #2
    Honda Eater Feedback Score 0 Mike-92RT's Avatar
    Join Date
    Sep 2010
    Owner Since
    April 2007

    Location
    Ontario, Canada
    Posts
    332
    Blog Entries
    1
    Thanks
    4
    Thanked 6 Times in 1 Post
    a bad MAS would make the car run like complete shit. But if he wants he can unplug the MAS and if it runs better then when its plugged in, theres his problem.

    It could be a vacuum leak, it could be a dirty IACV, it could be a dirty TPS, maybe even a boost leak? i dont know if a boost leak would cause rough idle or not.

    To test for a vacuum leak, spray intake cleaner all around your intake/throttle body/air intake pipe/vacuum lines, and if the engine revs up, then theres your leak.


    could also be the sparkplugs or coil packs. Tell him to get those checked.

  3. #3
    Southernmost 3S Owner supporter Feedback Score 0 93STLTH's Avatar
    Join Date
    Sep 2010
    Owner Since
    1996

    Location
    Key Largo, FL
    Posts
    1,059
    Thanks
    155
    Thanked 199 Times in 129 Posts
    A simple thing to check is the throttle body gasket. The little tab on the gasket should be towards the firewall, not the front of the car.


    2015 NG: Best in Show. Best Custom Interior. Best Custom Exterior. 2nd place,Best Engine Bay. 2nd place,Best 1st Gen. 2nd place,Longest distance driven. 3rd place, Coolest Accessories. 3rd place, Autocross Class 2
    2014 NG: Best in Show. Best 1st Gen. 2nd place, Best Interior. 2nd place, Furthest Distance Driven. 3rd Place, Peoples Choice. 3rd place, Best Engine Bay. 3rd place, Best Custom Exterior
    2013 NG: 1st place, FWD Drags
    2011 NG: Best Overall and Best 1st Gen. 3rd place Autocross FWD Modified and FWD Drags
    2009 NG: Best 1st Gen 3S and Best Interior. 3rd place, Autocross, FWD Modified.

    Mods include 18in. Moda wheels and BF Goodrich KDW's, Tein Flex suspension, R1 Concepts rotors, 3SX stainless steel engine dress up kit. Blue/black carbon fiber 575 hood, VLS and a full RT conversion. Audio mods include a Kenwood DVD touch screen HU, Kenwood speakers, Memphis audio 5 channel amp and 12" Subs. Corbeau Leather seats, carbon fiber dash trim and HID upgrade.

  4. #4
    Forum User Not Verified Feedback Score 0 marshallh's Avatar
    Join Date
    Sep 2010
    Owner Since
    6/08

    Posts
    48
    Thanks
    23
    Thanked 1 Time in 1 Post
    IAC, you can check with a multimeter here
    Vacuum leak somewhere
    FIAV in throttle body

  5. #5
    I'm Kind Of A Big Deal Feedback Score 8 (100%) Emilie@GZP's Avatar
    Join Date
    Sep 2010
    Owner Since
    2003

    Location
    Easton, Pennsylvania, United States
    Posts
    2,436
    Thanks
    216
    Thanked 106 Times in 90 Posts
    does it run better with the MAS unplugged? what year is the car?
    Circa 2005... Oh my, how far I've come
    Quote Originally Posted by Emilie@GZP View Post
    gear wrenches = wrench with the spinny thing inside of the circle part?
    Current:
    2004 ML500 - Mommy Mobile
    1996 Ram 2500 V10 - Tow Vehicle
    1991 Stealth R/T Twin Turbo - Pink Parts, Billet GZP 747's
    1995 3000GT VR-4 - lawn gnome
    1999 3000GT SL - 7,436 miles
    1995 3000GT Spyder - garage ornament

    FOR SALE:
    1995 3000GT Spyder VR-4 Red, 80k miles

  6. #6
    Drives a UFO Feedback Score 0 ilian51378's Avatar
    Join Date
    Sep 2010
    Owner Since
    2003

    Location
    Grand Cayman, Cayman Islands
    Posts
    160
    Thanks
    0
    Thanked 5 Times in 4 Posts
    Thanks for the input guys! I forgot to ask him what year the car is, but I will and I will report it here. I don't think he has tried to run the car with unplugged MAS, but I will tell him to do it...

  7. #7
    Drives a UFO Feedback Score 0 ilian51378's Avatar
    Join Date
    Sep 2010
    Owner Since
    2003

    Location
    Grand Cayman, Cayman Islands
    Posts
    160
    Thanks
    0
    Thanked 5 Times in 4 Posts
    Okay guys,

    I found out some more info that I didn't post... Well, when my friend bought the car, it was running on four cylinders. When he changed the ECU, the car started running perfect. However, after he changed the timing belt, the above described issue occured...

  8. #8
    Forum User verified Feedback Score 2 (100%) Boomer3000's Avatar
    Join Date
    Sep 2010
    Owner Since

    Location
    STL, MO
    Posts
    1,184
    Thanks
    192
    Thanked 36 Times in 29 Posts
    Then timing might be off... Double check that. If your lucky no damage has been done yet.
    1991 Stealth RT/TT
    Mods- Greddy Type S and a spun bearing.

    [Yesterday 11:43 PM] R/T93 : Im reading hulk comics on Youtube
    [Yesterday 11:45 PM] R/T93 : he has to fight the silver surfer hand to hand...
    OhioSpyderman:why do you have to pee on my wheaties Dave?

  9. #9
    Honda Eater Feedback Score 0 Mike-92RT's Avatar
    Join Date
    Sep 2010
    Owner Since
    April 2007

    Location
    Ontario, Canada
    Posts
    332
    Blog Entries
    1
    Thanks
    4
    Thanked 6 Times in 1 Post
    agreed /\

    when timing these engines, its hard to keep all 4 cams in place while tensioning the belt, so one of them could have came off mark? Cam lockers help BIG time, and also the tensioner pulley tool that 3sx sells.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
The 3000GT/Stealth/GTO Web History Project
3000gt.com
3000GT / Stealth International WWWboard Archive
Jim's (RED3KGT) Reststop
3000GT/Stealth/GTO Information and Resources
Team 3S
3000GT / Stealth / GTO Information
daveblack.net
3000GT/Stealth/GTO Clubs and Groups
Michigan 3S
MInnesota 3S
Wisconsin 3S
Iowa, Nebraska, Kansas 3S
North California 3000GT/Stealth
United Society of 3S Owners
3000GT/Stealth/GTO Forums
3000GT/Stealth International
3000GT/Stealth/GTO Event Pages
3S National Gathering
East Coast Gathering
Upper Mid-West Gathering
Blue Ridge Gathering