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  • celticnight
    celticnight - 1997 GMC Yukon - Engine - 9/30/2014
    Yukon help no start no check engine light
    I have a 97 yukon 5.7L it won't start no spark down the line. No check engine light. I tryed hooked up a obd2. Powers it but wont read it. Fuel pump dose not come on but in the fuel pump relay if I bypass the ecm port it turns on. I checked all fuses and thay are good.
     
    • jdl
      9/30/2014 jdl
      Did you check the ecm B fuse under the hood? Not only check the fuse, check voltage on fuse circuit, hot all the time. My hearing isn't much good, I can't hear the fuel pump run with engine cranking.

      Also, there shows to be a fuel pump/oil pressure switch. It's a redundant power supply to the fuel pump in parallel with relay. If switch is functional once you crank it enough to bring up oil pressure and the switch closes, the fuel pump will run, regardless of relay.

      During initial prime, no crank, the pcm sends voltage to control side of fuel pump relay, the ground for control side of relay is constant ground. If no initial prime because computer doesn't send voltage to control side of relay, Wiring circuit problem, voltage or ground, relay problem, computer problem.

      Does the battery have a full charge?
  • bossivey
    bossivey - 1994 GMC K1500 Suburban - Engine - 9/29/2014
    Suburban died tried to jump it it fired up smoke came out the hood and it died,y?
    I was about home and my Burban died, tried to start it and battery seemed drained, jumped it, after a few attempts it fires up, smoke comes out of the hood then dies. Tried to start it again and then same problem, battery seemed to drained to crank, so I attempt to ...
     
    0 answer
  • Don Covey
    Don Covey - 1999 GMC Sonoma - Engine - 9/22/2014
    My truck is not getting gas to the engine, but i can hear the fuel pump working. Whats wrong?
    135,000 mileage-Has been sitting all winter. Has started 3 or 4 times but quits running after about 3 or 4 seconds
     
    • jdl
      9/22/2014 jdl
      Use a gage and check for proper fuel pressure. How long since a tune-up? Check for injector pulse.

      At the moment, I can't rule out security system, where applicable.
  • marc
    marc - 1996 GMC C2500 Suburban - Engine - 9/22/2014
    At freeway speeds, when I take my foot off the gas pedal, the engine backfires loudly. Does not happen at lower speed.
    engine has 320k miles on it. The vehicle just started doing it one day.
     
    0 answer
  • Wayne
    Wayne - 1998 GMC K1500 - Engine - 9/17/2014
    Have whine coming from the front engine compartment that comes with rpm until around 2500.
    Replaced PWRs st fluid and flushed system and it got a little better. Could it be anything other than the pump? Has 190k and don't want replace it needlessly.
     
    • alex
      9/17/2014 alex
      take the belt off and rev it up if the noise is still there you know it is in the accessories spin everything by hand while pushing or pulling on then everything should be tight and smooth any roughness will turn into belt noise look at all of the pullies with teeth they shouldn't have a sharp edge on them if they do the pully is wore out if everything looks and spins good replace the tensioner. you should have to twist it pretty hard to get the belt off.
  • marcia
    marcia - 1994 GMC C1500 Suburban - Engine - 9/13/2014
    It won't start has new starter and battery there is power but it doesn't turn over whats wrong?
    could it be a fusible link?
     
    • CVO
      9/13/2014 CVO
      First, check the battery and starter cables for their tightness or free of corrosion and physical damaged.

      See this Starting system simplified diagram. Have a help from an assistant to crank the engine, use a 12 volt light tester or a digital voltmeter, apply it to the starter control circuit.
      If there is light or 12 volts and the starter isn't cranking, then the starter is the culprit. Have the starter to bench test for free at the local auto parts stores.
      If there isn't no light or no volts, then the ignition switch is the culprit.
      Check the starter relay and position the Automatic transmission shifter in neutral.

      http://www.samarins.com/glossary/starter.html
  • Uflores
    Uflores - 1994 GMC C1500 Suburban - Engine - 9/9/2014
    Why does my car turn off at a stop sign?
    When I turn on the car the car takes awhile to start than normal. When you are at a complete stop the RPM starts going up and down between 0 and 1, and then turns off. It also turns off when your about to reverse. I work at a car dealership and no mechanic in the ...
     
    0 answer
  • Barb.desrosiers
    Barb.desrosiers - 2008 GMC Envoy - Engine - 9/7/2014
    What is wrong with my car? see additional details
    Initially I was having trouble starting the car. I would get a click click whine noise, then sometimes I would turn key and nothing happened, I would turn key 3 or 4 times with nothing happening, then all of a sudden it would start. Then I was sitting at a stop ...
     
  • Barb.desrosiers
    Barb.desrosiers - 2008 GMC Envoy - Engine - 9/7/2014
    What is wrong with my car? see additional details
    Initially I was having trouble starting the car. I would get a click click whine noise, then sometimes I would turn key and nothing happened, I would turn key 3 or 4 times with nothing happening, then all of a sudden it would start. Then I was sitting at a stop ...
     
    • CVO
      9/7/2014 CVO
      This vehicle has a similar problem to this post.

      http://www.automd.com/.../


      Try this tip.

      First, check the battery and starter cables for their tightness or free of corrosion and physical damaged.

      See this Starting system simplified diagram. Have a help from an assistant to crank the engine, use a 12 volt light tester or a digital voltmeter, apply it to the starter control circuit.
      If there is light or 12 volts and the starter isn't cranking, then the starter is the culprit. Have the starter to bench test for free at the local auto parts stores.
      If there isn't no light or no volts, then the ignition switch is the culprit.
      Check the starter relay and position the Automatic transmission shifter in neutral.

      http://www.samarins.com/glossary/starter.html

      Note: a 3/4 charge battery is 12.50 volts
      A discharge battery is 11.75 volts.
      A battery under a cranking load and it is reading less than 7 volts,it will be a recycled battery.
  • msyoung
    msyoung - 1997 GMC K1500 - Engine - 9/4/2014
    Will not start turns over just doesn't stay onthis happened after running out of gas & putting out in neutral to star
    Recently changed fuel pump and filter
     
    • jdl
      9/4/2014 jdl
      Did you check fuel pressure? If you have the spider fuel system, that system is known for problems. How long since over-all tune-up? Any applicable trouble codes? To check codes yourself, at the least you need an obd2 code reader.

      Can you tell if your losing spark--fuel pressure or something else?
      jdl
      9/4/2014 msyoung
      Did change spark plugs and haven't yet check the fuel pressure no check engine light so no code..
      Someone had said it might be starter idk
      jdl
      9/4/2014 jdl
      I always check for codes, I've had inactive codes point me in the right direction. I don't think I understood your last sentence? If it cranks ok, the starter isn't the problem.
      jdl
      9/4/2014 msyoung
      Humm im going to have to try the code scanner
      Wish I could post a video of what it is doing
      jdl
      9/5/2014 jdl
      A start and stall could be caused by almost anything. Maybe your losing rpm signal--fuel system is running too rich or too lean for some reason. Anti-theft issue where applicable. Many possibilities.
  • ken lehtonen
    ken lehtonen - 2005 GMC C5500 Topkick - Engine - 8/29/2014
    Diesel engine wont start . when it starts it runs good
    seems like an electric problem , no power to fuel pump when trying to start but when it starts it works fine. replaced fuel filter and pumped up fine started and ran shut off and wont start
     
    0 answer
  • coreybaker86
    coreybaker86 - 1995 GMC K1500 - Engine - 8/28/2014
    No power to the OBD2 connection.
    Recently bought the truck and it runs good but cruising around 55 the engine rev's up suddenly by maybe 500-700 rpms then goes back to normal. I cant accelerate during this either. I plugged in a scan tool and it wouldnt turn on. I checked the scan tool on my other ...
     
    • jdl
      8/28/2014 jdl
      Some gm makes and models, 95 is a crossover year, It could be a hybrid connector, I can't you with that type connector. I'll check your wiring diagram.

      If you fully obd2 compliant, pin 16 should be hot. That voltage usually comes from cigar fuse, I'll have to double check.
      jdl
      8/28/2014 jdl
      If your system is obd 1.5, then you will need a scanner for obd 1.5.
  • glen
    glen - 2001 GMC Sonoma - Engine - 8/26/2014
    No start intermittent
    intermittent crank but no start fixes itself after days or weeks of trying to start it
     
    • jdl
      8/26/2014 jdl
      When the problem is ongoing, if it cranks good but won't start, have a helper crank it while you visually check for spark at the spark plugs. If you have spark everywhere, check fuel pressure. With intermittent issues, you need to test when problem is ongoing.

      Check for intermittent rpm signal? No rpm signal, no start. Can be intermittent.

  • glen
    glen - 2001 GMC Sonoma - Engine - 8/26/2014
    Intermittent no start
    mileage 125000 cranks but no start can happen anytime works fine most of the time but will leave you stranded let it sit for days or weeks and eventually starts and acts normal until next episode of no start
     
    0 answer
  • rlhanson58
    rlhanson58 - 2008 GMC Acadia - Engine - 8/25/2014
    Where is my oil pressure switch located on my engine.
    Having a problem with low oil pressure. I check oil it's fine. This only happen on a long trip. light come on dash board.
     
    0 answer