GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 2 of 2
  1. #1
    Sr. Apprentice cedicol's Avatar
    Join Date
    Feb 2012
    Blog Entries

    Default Help needed for start up.

    So i drive a GMC suburban from 1996. Two days ago the truck strated like it should. Yesterday the engine was turning over but he diddent want to fire up. I have gas on the engine but i noticed when i pulled out a spark plug that i have a weak egnition. So i tried with the help of a friend to change the coil and ICM. I just took the coil and ICM of my friends truck and putted it in to mine to see if the problem whas fixt with this or not. Well it is not. I have a scantool and it gives me the codes P0420 and P0430. That is catalyst system efficiency below thershold (bank 1 and bank 2). I have a leak on the exhaust on bank one and i only have one cat so i think that would be the triger for those codes. But can this be the reason the engine dont start? Can sombody help me to a direction what to do now???? HELP
    life sucks, but i love it!!!!

  2. #2
    Sr. Engineer
    Join Date
    Oct 2010
    Indianapolis, In


    Look for 55 to 60 PSI from the fuel pump to be sure it is sufficient. Try putting some fuel or starter fluid in the intake and see if it starts for a few seconds. If it does, then start looking for a fuel delivery problem.
    2000 GMC YUKON SLT, 5.3L tow pkg, G80 rear/w 3.73 gear

Similar Threads

  1. hard start or wont start 305.
    By timhall1787 in forum General Chevy & GM Tech Questions
    Replies: 4
    Last: 09-29-2011, 09:00 AM
  2. 7.4L Hot Start (harder to start)
    By rowekmr in forum GM Powertrain
    Replies: 1
    Last: 01-04-2011, 02:01 AM
  3. Pic needed
    By 92'Jimmy in forum Chevy Blazer Forum (GMC Jimmy)
    Replies: 2
    Last: 11-14-2009, 12:22 AM
  4. Car was hard to start then didn't start at all
    By bmxr123 in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 1
    Last: 07-03-2009, 08:48 AM
  5. help needed
    By GM_Guy in forum The Coffee Shop ~ Chit Chat
    Replies: 2
    Last: 08-30-2007, 08:36 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts