03 z71 issues help asap please

Discussion in 'GM Powertrain' started by CD82, Oct 11, 2012.

  1. CD82

    CD82 New Member

    ok i have a 2003 z71 silverado its got the 5.3l in it with 4l603 transmission.
    ive been having issues for quite sometime now with it losing rpms and dying at ide speeds.
    such as when im comming to a stop light or sign or go to park in a parking lot.
    the tach will drop and the truck will fall on its nose an dye.

    ive done as suggested by mecahanics and the chevy house
    cleaned throttle body and MAF and the air intake filter.
    changed plugs and plug wires changed the fuel filter.

    and this problem still occurs ive heard it could be the drive by wire throttle body.
    or could be a leak in the intake gasket
    now ive priced a gasket and its about 70$ and i have a chiltons book.
    but is there a way i could test for this without a smoke machiene or ?

    could someone help with some issues here?
  2. the phantom

    the phantom Epic Member 5+ Years ROTM Winner 1000 Posts

    Welcome to the club!! Is your check engine light on? If it is have the trouble code read and that may lead to your issue. If its not on then I would think that it would not be your intake gasket as a manifold absolute pressure (map) sensor should trigger the CEL because of inconsistant readings. Good luck and we hope to see some pics of your truck!!
  3. CD82

    CD82 New Member

    check engine lite has been on since ive got the truck and only codes it shows are the o2 sensors.
    it has headers all people ive spoken to about that says theh eaders are prob why check engine lite is on.

    thats the only code it has ever showed

    hehe my truck is ugly has to many issues for pics kinda embarrased of it
  4. ChevyBoy2009

    ChevyBoy2009 Rockstar 4 Years 500 Posts

    Fuel pump??...my old 03 silverado had a fuel pump go out at 120k and when i took it out to replace it,it already had a junkyard fuel pump in it...
  5. CD82

    CD82 New Member

    i seem to be getting 58lbs to the fuel rail from the pump
  6. TimTom64b

    TimTom64b Epic Member 5+ Years 500 Posts ROTM Winner

    I would guess the its not getting enough fuel at idle... Maybe MAF sensor, fuel filter or fuel pump.
    I'm sure others will chime in.

    And yes headers will cause lean codes to trigger on bank1 and 2... Mine did hense my purchase of the trinity and custom tune from diablew tune.
  7. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    I had the same stalling issue with an 03 yukon xl. When I bought it, it would bog down and stall at lights. turned out to be a bad battery and alt
    Last edited: Oct 12, 2012
  8. CD82

    CD82 New Member

    ive replaced the fuel filter checked hte pressure of the fuel pump appears ive got 58lbs to the rail.
  9. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    I understand that, as you posted that information in a previous post. I was just stating that I had a 03 truck that did the exact same thing. It turned out to be the battery. If you know that you have bad 02 sensors then you need to fix that or the computer will give the wrong commands for fuel, spark advance and spark retard. The bad O2 sensors can destroy your MPG also. If you have duel exhaust and the sensors are not installed then you need to install o2 replicators.
  10. CD82

    CD82 New Member

    my mpg is great actiualy 15 mpg in town i think that is decent

    i will get the alt and battery checked the battery seems to hold a very good charge
    from what the guage says in the dash but i have them chekced to make sure

    battery is less than a year of it it turns out to be that then i can get it replaced.

Share This Page

Newest Gallery Photos