1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

hesitation between 2k - 3k RPM - 03 2.7L

Discussion in '1st Gen. Tacomas (1995-2004)' started by r0ss, Dec 2, 2014.

  1. Dec 2, 2014 at 9:21 AM
    #1
    r0ss

    r0ss [OP] Active Member

    Joined:
    Oct 31, 2009
    Member:
    #25241
    Messages:
    42
    Gender:
    Male
    First Name:
    Ross
    SFO > LAX > AUG > ATL
    Hello, Thanks in advance for any help you can share. I have searched the forums and have not found anything with the same symptoms. If I missed something, I apologize.

    I have a 2003 Tacoma with a 2.7L engine and a manual transmission. It has around 130,000 miles on it. It is a California/50 state emissions model.

    I have recently noticed a distinct hesitation / lack of power between 2000 and 3000 rpm. I have noticed that it is more noticeable when it is colder outside (Below 40ºF). I believe that it is worse when the engine is cold, but it does continue after the engine is hot. I have not had a check engine light come on.

    When I first noticed the hesitation, I thought it felt like the engine was starving for air. I checked the air filter and found it was clogged with crushed up leafs (got to love fall). I replaced the air filter and the problem seemed to go away. Now about 7-10 days later the problem has returned. I checked the air filter and it still looks brand new and the intake beyond the air filter looks totally clean with no dust or build up. I did replaced the spark plugs about 9 months ago, and while I have not checked them recently, I am assuming they are not the problem.
    My first thought was that it must be a vacuum leak. I inspected all of the vacuum lines I could find and didn't see anything that looked bad. With the exception of the lines that goes from the airbox, across the radiator to over near the brake booster. I ordered a replacement for this line, just to be safe. The truck idles strong and stable.

    Is there anything simple I am missing?

    I should ad that I checked the inside of the oil cap and the dip stick- there is no sign of moisture or frothiness nor is there any smoke coming from the exhaust.

    I also recently noticed a faint smell of hot anti freeze while I was checking the air filter. There was some residue on the top of the radiator and fan shroud, near the top hose. I cleaned it and will monitor the area and the coolant reservoir for leaks.

    Any tips or suggestions would be highly appreciated.

    Thanks!
     
    Last edited: Dec 2, 2014
  2. Dec 2, 2014 at 9:26 AM
    #2
    97TacoNM

    97TacoNM Riding a 97 Taco

    Joined:
    Aug 10, 2014
    Member:
    #135833
    Messages:
    465
    Gender:
    Male
    First Name:
    Jim
    NM
    Vehicle:
    97 Taco LX 4x4 Ext Cab
    Rampage halogens Custom bed rack
    You may want to clean your throttle body and MAF sensor. Easy to do, costs very little, a self fix kind of job. If it is an electronic TB, which it probably is, just have someone push the gas pedal all the way to the floor (engine not on) to open the throttle, and don't push on it to move it, as it could damage it. If it is a manual, cable controlled TB, you can move that valve manually.
     
  3. Dec 2, 2014 at 9:28 AM
    #3
    r0ss

    r0ss [OP] Active Member

    Joined:
    Oct 31, 2009
    Member:
    #25241
    Messages:
    42
    Gender:
    Male
    First Name:
    Ross
    SFO > LAX > AUG > ATL

    Thanks! I will give that a shot. It is a cable TB, so it should be pretty easy. I will post results.
     
  4. Dec 2, 2014 at 9:28 AM
    #4
    keakar

    keakar Well-Known Member

    Joined:
    Oct 2, 2014
    Member:
    #139537
    Messages:
    5,258
    Gender:
    Male
    First Name:
    karl
    louisiana
    Vehicle:
    2006 4runner sport 4.7L V8 (white)
    used to have - 99 2.4L I4 5 lug & 04 prerunner v6
    yep, clean the MAF sensor (only with MAF cleaner or you ruin it) and clean the throttle body and IAC.

    those are the main problems that get dirty over time

    look at youtube for videos for most all maint items you need to do https://www.youtube.com/playlist?list=PLidCGcjQT-XKRS3Bx0B0UNSLZ1RSdHnri

    as I mentioned, there are very few things you still clean with carb cleaner anymore so if it has any wires for anything then DONT USE CARB CLEANER but if its a generic metal part with no electronics attached then carb cleaner would be ok, otherwise use electronics safe cleaners only
     
    Last edited: Dec 2, 2014
  5. Dec 2, 2014 at 12:17 PM
    #5
    97TacoNM

    97TacoNM Riding a 97 Taco

    Joined:
    Aug 10, 2014
    Member:
    #135833
    Messages:
    465
    Gender:
    Male
    First Name:
    Jim
    NM
    Vehicle:
    97 Taco LX 4x4 Ext Cab
    Rampage halogens Custom bed rack
    ^^ Yes. Get ONLY Throttle Body cleaner, and ONLY Mass Air Flow sensor cleaner. Plus a toothbrush to destroy and a non-lint-making rag.

    If your TB looks really grody, you may consider grabbing a new gasket and removing it completely from the mani, so you can really scrub it down good. You should be able to take care of it still attached, but if the buildup is gnarly (I am, like, totally in the 80's speak right now) a good bench cleaning can do wonders. Might as well put in a new PCV valve as well, they are super inexpensive.

    Just be ready for possible rough idling initially after the cleaning as you burn up any residual cleaner. Only momentary. It should all evap before you reconnect the air assembly, but I always prefer to make sure it has before I run it again, to keep from throwing MAF codes.

    Good luck!
     
  6. Dec 7, 2014 at 1:53 PM
    #6
    r0ss

    r0ss [OP] Active Member

    Joined:
    Oct 31, 2009
    Member:
    #25241
    Messages:
    42
    Gender:
    Male
    First Name:
    Ross
    SFO > LAX > AUG > ATL
    Thanks for the tips! I cleaned the MAF and the TB. The MAF looked brand new, but I cleaned it anyway. The inside of the TB was pretty gunky. I also replaced the PCV, and fuel filter. So far, the weather has been on the warmer side, so I can't say for sure if this fixed my problem or not, but I guess I will find out.

    Thanks for the tips and thank for clarifying the need for the specific cleaners. I probably would just have used carb cleaner.
     

Products Discussed in

To Top