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System running lean/rough idle 1999 3.4 v6

Discussion in '1st Gen. Tacomas (1995-2004)' started by NotstockTRD, Oct 22, 2009.

  1. Oct 22, 2009 at 1:52 PM
    #1
    NotstockTRD

    NotstockTRD [OP] TRD

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    I checked all my vacuum lines -everything is secure..
    I cleaned my throttle body...
    it could be mass air flow sensor but it didnt look dirty- what does it look like if its dirty?(i didnt clean it)
    Idle air control valve may need cleaning/ replacing?
    i used to have a cold air intake but took it off months ago and problems and check engine light(system too lean) just arrived?
    what should i do to fix this issue? I like to do all the work on my truck to avoid paying for labor and diagnosing....
    Anyone else have this issue or any advice on what it could be???
    thanks in advance
     
  2. Oct 22, 2009 at 2:08 PM
    #2
    NotstockTRD

    NotstockTRD [OP] TRD

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  3. Oct 22, 2009 at 2:36 PM
    #3
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    Could be alot of things....Did the engine throw a code?
     
  4. Oct 22, 2009 at 2:40 PM
    #4
    NotstockTRD

    NotstockTRD [OP] TRD

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    yeah forget the # but it read engine running too lean
     
  5. Oct 22, 2009 at 2:46 PM
    #5
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    4.10 gears, sliders, and lots of buttons.
    Lots of things can cause that. Kinda need the code to narrow it down, and see what systems are being affected.
     
  6. Oct 22, 2009 at 2:52 PM
    #6
    NotstockTRD

    NotstockTRD [OP] TRD

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  7. Oct 22, 2009 at 3:06 PM
    #7
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    4.10 gears, sliders, and lots of buttons.
    Use some electronic contact cleaner, and clean the MAF
     
  8. Oct 22, 2009 at 3:07 PM
    #8
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    4.10 gears, sliders, and lots of buttons.
    Also, consider replaceing the fuel filter.
     
  9. Oct 22, 2009 at 3:12 PM
    #9
    4WD

    4WD cRaZy oLdmAn

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    Grey wire MOD, deck plate, diff breather MOD, 2nd gen. OME 883# on Tundra 5100's, OMD custom 3" leafsprings, rear shock relocation, Ivan Stewart TRD rims w/285/75/16's, '02 bumper MOD, Famous Fabrications sliders , LED interior/exterior lights, bed bar, Custom tube bumper, Old school KC day lighters,Red Ring 8" HID flood, Kenwood vhf 2M.. umm some other shit I'm forgetting right now
    All vehicles these days are so buried in electronics & emissions that its almost impossible to just "have a hunch" & be right cause several key emissions equip. can fail & cause the same condition so narrowing the code is pretty key in gettin' to the heart of the matter so ya don't waste alot of time and $$$$ just throwing at the problem, anyway need more info, miles ?, could be an 02 sensor, a plugging up fuel filter,(check fuel pump pressure) a CATALYTIC getting ready to shit. As far as vacuumm lines go you can't just give them the ol' once over & assume its all good, with engine running, take a little aerosol chemtool or just about any other type spray, & while idling spray the lines & connections, & other hard to get to places & see if idle changes noticeably, if idle speed picks up then you can start looking for a VAC. leak somewhere, but still you really need to isolate the codes & defs. so you can have a better chance of fixing your problem in a timely manner.....GOOD LUCK ....:cool:
     
  10. Oct 22, 2009 at 3:18 PM
    #10
    NotstockTRD

    NotstockTRD [OP] TRD

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    i have 145,xxx miles do you think the fuel filter could go bad?
    Also, what does a dirty MAF look like? sounds dumb but mine didnt have any dirty gunky build up on it?? could it still be dirty?
    thanks
     
  11. Oct 22, 2009 at 3:20 PM
    #11
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    4.10 gears, sliders, and lots of buttons.
    You might not be able to see the accumulation of dirt on the MAF. Its a good idea to clean it every so often. I belive the fuel filter is required to be changed every 30K miles on your truck.
     
  12. Oct 22, 2009 at 3:21 PM
    #12
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    4.10 gears, sliders, and lots of buttons.
    FWIW, The fuel filter is loc ated on the frame on the driver side, near the driver door.
     
  13. Oct 22, 2009 at 3:30 PM
    #13
    NotstockTRD

    NotstockTRD [OP] TRD

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    thanks chris and 4wd -new fuel filter is only 20 bucks so might as well change it...
    I will spray down my MAF as well..
    ITs weird because the rough idle prob came up about 2 months ago(while at a stop light, idle stumbled) but then went away but now its back.. its still drives great under load though...
    frustrating as hell
     
  14. Oct 22, 2009 at 3:32 PM
    #14
    shitroc

    shitroc Master of War

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    i had the same problem for months man, drove me crazy. the cel would come on and it wouldn't just be system to lean, it would be 3 or 4 codes. i cleaned the maf thinking that would help, didnt work. replaced maf, that didnt work. cleaned both o2 sensors still no luck. so i decided to spend the couple hundred bucks and buy a new o2 sensor(bank 1 sensor 1, the one closest to the engine). Worked perfectly, cleared everything up. Pain in the ass to change though.
     
  15. Oct 22, 2009 at 3:35 PM
    #15
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    4.10 gears, sliders, and lots of buttons.
    When was the last time the plugs were changed?
     
  16. Oct 22, 2009 at 3:40 PM
    #16
    NotstockTRD

    NotstockTRD [OP] TRD

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    4 years ago toyota wires and bosch platninum 4 plugs top dollar shit never caused anything but good
     
  17. Oct 22, 2009 at 3:41 PM
    #17
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    Your better off with the OEM twin ground plugs.
     
  18. Oct 22, 2009 at 7:23 PM
    #18
    NotstockTRD

    NotstockTRD [OP] TRD

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    that maybe so... however the truck has not had an issue with plugs or wires.. its been four years of perfection! that cant be the issue
    any other suggestions?
     
  19. Oct 22, 2009 at 7:29 PM
    #19
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    Actually, that COULD be the issue. those +4 plugs are known for causeing issues in the 3.4 and the 4.0. Your better off running the OEM twin ground plugs. If you changed the fuel filter, and cleaned the MAF, the plugs would be the next step.
     
  20. Oct 22, 2009 at 7:34 PM
    #20
    NotstockTRD

    NotstockTRD [OP] TRD

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    If thats the case why would have ran fine for 4 years without a single prob?
     
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