engine starts but dies

Discussion in 'Chevy Blazer Forum (GMC Jimmy)' started by rtsee, Dec 3, 2013.

  1. rtsee

    rtsee New Member

    2002 Chevy Blazer with 4.3l vortec. When you crank it, it will not run for more than 3 seconds. Fuel pressure is 64 psi. Spark tester shows spark as for as long as you crank it. Security light comes on when you turn the key to runs and goes out after a couple of seconds. New cap rotor wires. help please?
  2. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    Welcome to GMTC! Seems like you are the third person in recent months with this issue.

    Here is one of the threads:
  3. rtsee

    rtsee New Member

    No in the other thread they talk about no spark. I have plenty of spark, but even with carb cleaner down the intake it will not keep running...
  4. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    Are you getting spark at the correct times? Maybe you have a timing issue.
  5. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    I'd need more testing, but from here if you can get it to start with a little carb cleaner, you have a fuel problem.

    I don't know what is in the carb cleaner, but a little starting fluid (ether) might be a better test. Propane is also a good fuel to test with.

    If you can get it to run with the starting fluid, or with the propane (use the propane torch without lighting the torch, turn it on and direct the gas into the the throttle body), you have a fuel delivery problem, or a fuel quality problem.
  6. TRPLXL2

    TRPLXL2 Epic Member 5+ Years 1000 Posts

    Vats, vats< vats
  7. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    Agree 100%. You said that you are getting spark while cranking. The vats system shuts spark off a few seconds after starting if the proper resistance is not found by the system. Google vats system repair. You will find things as basic as cleaning the chip on the key to as involved as adding a resistor to restore function
  8. MAD JAX

    MAD JAX Member

    My daughters '01 Jimmy has had the EXACT same symptom (cranks, flares, and dies) w/"Security" lamp "ON" then "OFF" @ 5 seconds KOEO ever since the local GMC "Dealership" attempted to "Flash" the Body Control Module (BCM) for Its "Air Bag" system warning lamp (ON) and Dome-Lamp "stays ON (unless "Dome Defeat" was depressed) all-the-tiime"...just over 6 months ago, and it's only "Crank/Flares/Dies" since, otherwise EVERYTHING worked just fine!

    However, that "Security" lamp WAS flashing when the "Dealership" attempted to re-program the BCM ~ something THEY surely KNOW should NOT be done...I didn't at that time...as-such ~ whom else could know that such "Disablement" would happen : ?

    I've since learned that if a PassLock II "Security" lamp is "flashing" and the vehicle looses Battery Power OR an attempt to "Flash" is made the BCM/VCM (Vehicle Control Module) the vehicle WILL BECOME DISABLED ~ exactly as discribed.

    Just yesterday a FOURTH "Mobile Independant" -- this time equipped with Factory/OEM Hardware/Software vs. the likes of "EFI LIVE", etc. -- diagnosed Ours as having a defective BCM, and I'm now trying to source a replacement BCM...which interestingly too ~ is appearing to be a "Dealer Only" item... : ?

    Here's ONE solution to effectively ommitting "PassLock II" from Your vehicle ~ that is ONCE YOU GET IT STARTED and "RUNNING" : ?


    I guess I'll see ~ to You Good Luck!
  9. MAD JAX

    MAD JAX Member

    Being the only alternative to taking it BACK to any "GM DEALERSHIP" for their subscription to "OEM" Factory-Specific Programming (vs. what the "Hot-Rod Tuners" think they can...and then find-out they CAN'T do ; ) I had a "Mobile Diagnostic Services" firm come-out 'n diagnose the vehicle, and -- after having determined several functions failing dispite valid serial communications data on "The BUS" they determined:


    So I did that ~ and learned something ELSE that the original "Dealer" servicing the vehicle 6 months ago SHOULD HAVE KNOWN BEFORE TRYING TO "FLASH" THE VEHICLE...that the WRONG BCM P/N had been installed in the Vehicle all-along!

    I had told them (GM Dealership) it was reportedly CHANGED by the previous owners "Tech" that never fixed the car...that they should VERIFY the correct P/N was installed IF they wound-up interfacing the DLC...that's something I HAD THEN ASKED THE TECH ~ which He confirmed "OK" ~ at that time when they'd brought me to see It ~ NOW as "DEAD-WEIGHT" in His Service Bay that first day, so WTF!!!

    So I bought one (from another GM Dealer) to install and -- per-instructions FROM BOTH "Dealer" and "Mobile Diagnostic Services" -- had the latter return to "Reprogram BCM"... : ?

    But because THIS particular BCM comes "Pre-Flashed" -- something no-one told ME! -- basically what-they-did for that $100 bucks was "Verify Communications" (something they'd already done) then initiate the "10-minute Key Relearn" proceedure (I could've done the "30-minute re-learn proceedure") and then crank-it-over...

    And it started-up...and then RAN ~ for the first-time in over 6 months!!!

    All of My Keyless Remote "Lock/Un-Lock" functions are WORKING AGAIN, including "Panic", etc., and too, the "Dome Override" control of the Headlamp System "Daytime Running Lights" (DRL) as-well!

    My "Air Bag" lamp is OFF w/NO DTC's present in that system (had a U-1000 DTC) and we found the "Dome Light Stays On" problem remains ~ as-related to a bad Door Handle Switch, which when actuated tells the BCM someone wants INTO the vehicle and so ILLUMINATE the interior lamps for an entry OR activate the Alarm System/Vehicle Theft Deterrent...and I've never been-so-glad to hear the Horn-Honk'n Lights-Flashin' ~ Hoo-Rah!!!

    My wife drove the car to work this morning "just to see...", and We'll give it to my daughter this weekend ~ 6 months AFTER She started College... : ?
  10. edsmagichands

    edsmagichands Member 2 Years 100 Posts

    glad to hear it's finally resolved! also thanks for keeping us updated, you have provided some valuable info that will hopefully help others!

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