Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

rpm drops

Discussion in 'The Garage' started by aaf815, Jan 29, 2006.

  1. aaf815

    aaf815 Registered Member

    Joined:
    Jul 9, 2005
    Posts:
    30
    Likes Received:
    0
    Location:
    socal
    i have a proplem with the blazer when the blazer is in parked and its ideling it sound like its going to turn off. sound like the rpm drops and then it goes up and drops again. whats can it be?and the motor is a 350 tbi
     
  2. dhcomp

    dhcomp 3/4 ton status Premium Member

    Joined:
    Mar 17, 2001
    Posts:
    9,853
    Likes Received:
    280
    Location:
    Truckee, CA
    my first guess would be fuel pump, or clogged fuel filter.....

    but lets see what the more experienced guys here say.....
     
  3. Chaddy

    Chaddy 1/2 ton status GMOTM Winner

    Joined:
    May 23, 2005
    Posts:
    4,110
    Likes Received:
    2
    Location:
    Salt Lake City,Utah
    plugs and wires mabey.
     
  4. Bushido

    Bushido Registered Member

    Joined:
    Jan 25, 2006
    Posts:
    38
    Likes Received:
    0
    Location:
    Hawaii
    350 tbi

    First off definitely check the basics like said above.Is the "check eng lite" on?---I would check the throttle body for carbon buildup between the blades and bore.Clean with throttle body cleaner and clean rag or old toothbrush.Check throttle body base gasket,these are common for breaking causing a vacumn leak.This usually causes a high idle but since it's very easy to check...Possible I.A.C. valve but that would be difficult to check without the right tools.---EGR valve may be stuck open.

    If you can give more info. would be helpful.
     
  5. resurrected_jimmy

    resurrected_jimmy 1/2 ton status

    Joined:
    May 23, 2005
    Posts:
    2,241
    Likes Received:
    0
    Location:
    back home in Houston
    Is it throwing any codes? that would be very helpful, sounds kind of like the computer is confused and reverting to limp mode
     
  6. aaf815

    aaf815 Registered Member

    Joined:
    Jul 9, 2005
    Posts:
    30
    Likes Received:
    0
    Location:
    socal
    the check engine lite is not on. throttle body is clean.
     
  7. sandawgk5

    sandawgk5 3/4 ton status

    Joined:
    Oct 28, 2003
    Posts:
    6,881
    Likes Received:
    1
    Location:
    Kitsap County PACNORWEST
    Surging on TBI I have always been told to check the TBI to Intake gasket. If it is pulling air under the gasket it will surge. Use carb cleaner and spray along the base of the TBI. If the idle smoothes out it is a bad gasket.

    Ooops did not see it was already posted.

    Ira
     

Share This Page