1999 Chevy C1500 Suburban LT - Crank, No Start

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by southsidesmoka, Mar 15, 2017.

  1. southsidesmoka

    southsidesmoka New Member

    I need a little help, folks...if you please...

    My beloved Suburban, affectionately named "The Bus", simply would not start without a boost. I recently had new O2 sensors installed. The air filter is clean. It can breathe. I figured the issue was electrical in nature since the boost in current always seems to do the trick; so, I installed an Optima YellowTop deep-cycle battery. That solved the problem for about 12 hours.

    The Bus was back to it's original non-starting condition. After some unsatisfactory multi-meter test measurements, I put in a new ignition coil, distributor cap (the old one had some how formed corrosion on the inner tower and center terminals), distributor rotor, sparks plug and their wires. I figured that would definitely absolve The Bus of any hiccups in the ignition process. I was wrong.

    I bought a Bosch OBD-1150 code reader to try and save the several hundreds my mechanic's shop was going to charge me to diagnose and fix whatever the problem is. The only code The Bus threw was an Anti-Theft P1361 if I'm not mistaken about the code number. Nothing "serious" like I was expecting.

    I disconnected both battery terminals for approximately ten minutes this morning and then reconnected, hoping this little trick would prove to reset any Anti-Theft or other problems, alas, to no avail. The Bus simply will no start without a boost. I dry scrubbed my battery terminals with a metal bristle brush to remove contaminants and improve conductivity and installed new battery bolts. No change - plenty of crank but no start.

    I figure if The Bus starts with a boost, the fuel pump and line are not the issue...right? It would seem, logically, like an electrical issue to me. However, either it's not, or I have ceased to locate the problem thus far.

    Simply put, I have angered the gods GM and Chevy has struck me down. I need help. Any suggestions are greatly appreciated, welcomed and needed. Thanks in advance.

    - southsidesmoka
  2. thegawd

    thegawd Rockstar 2 Years 1000 Posts

    What kind of motor does your 99 Burb have? 5.7 I believe right...
    I think your either having a parasitic draw, such as a light on, check your visors, especially the passenger side, glove box and underhood light.

    Or you may have bad grounds... check them all, disassemble, clean with a wire brush to bare metal, put some dielectric grease on them and the connections and reassemble. Neg post to fender beside it, firewall under passenger side heater hoses to the frame, and then from that same spot on the frame down n up through a heat shield and up to the back, top, rear passenger side of the engine block.

    silverado002 likes this.
  3. silverado002

    silverado002 Rockstar 3 Years 1000 Posts

    In addition to what Al said above, you could measure the voltage at the fuel pump when cranking.
    thegawd likes this.
  4. CaptBob

    CaptBob Member

    can you here the fuel pump cycle when you turn the key on and then shut of after a few seconds? I have had issues starting hard or having to crank excessively with a fuel pump relay needing replaced. This is an easy check, the pump will operate after you crank, but until you start cranking if the relay is bad it won't pre pressurize the injection, you had to crank it to get it pumping. Then you were fine once it started.
  5. kennyb79

    kennyb79 Rockstar 100 Posts

    i'd have to do some research, but isnt there an electronic anti theft device on there somewhere? something elecctronic that disabled the engine?
  6. kennyb79

    kennyb79 Rockstar 100 Posts

    "Certain years of Gm products that have the passlock II systems. With this de-mobilizing system the contacts inside of the ignition system has to read current through the key. Although my key's weren't "chip" keys they still have to have the voltage read through them. When the contacts inside the ignition become wore to the point they will not conduct any longer the system assumes there is no key and the vehicle is being started by other means thus engaging the security feature.This is also the reason it gets worse and takes longer to disengage the security after time, the contacts only wear more over time taking longer to read the correct resistance values through the key. Many times the contacts can be cleaned by electrical cleaner being sprayed into the switch then pushing the key into the ignition multiple times. "
  7. southsidesmoka

    southsidesmoka New Member

    Yes sir, you are correct - the 5.7L. I'm trying to find the source of any parasitic drain - I just came in from measuring the voltage across my terminals and am disappointed to report that my multi-meter read 11.85VDC. I have a 4-gauge power line running to the cargo area for audio equipment, but it has been disconnected for days to troubleshoot this very problem. I checked everything I could think of once. Then I checked it again. Apparently, I am simply missing the site of this parasitic drain.

    - southsidesmoka
  8. southsidesmoka

    southsidesmoka New Member

    If I can locate those pesky fuel pump wire leads, I'm on it boss. I hear the pump activate and de-activate with key-on and key-off, respectively. Thanks for the suggestion, brother.

    - southsidesmoka
  9. southsidesmoka

    southsidesmoka New Member

    Fuel pump relay, you say? It's now on my list of things to check for malfunction, along with the fuel pump voltage and the location of this parasitic drain. Thanks, bossman.

    - southsidesmoka
  10. southsidesmoka

    southsidesmoka New Member

    Thank you, kindly. I'm looking into every possible point of failure and this is definitely one I need to look into...my Bosch OBD-1150 read an Anti-Theft code in the Suburban's computer memory. I cleared it and it hasn't been thrown since. Another trip to the auto parts store for electronic cleaning fluid/spray. She's either gonna run or I'm gonna die trying! :D

    - southsidesmoka

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