97 Suburban Intermittent No Start

Discussion in 'General Chevy & GM Tech Questions' started by getawaycars, Apr 11, 2010.

  1. getawaycars

    getawaycars New Member

    My 97 K1500 4x4 5.7L 176,000 miles has not started on two occasions (three weeks apart), most recently yesterday. It starts later and is ok, but seems to crank a little longer before starting (all the time). It also backfires when starting (very infrequently - less than once a month).I have replaced the crank poision sensor and fuel pump relay, as well as recent cap, rotor, plugs, wires, fuel filter.

    My system doesn't hold fuel pressure, with key on (but not running) pressure goes to 45 psi, but drops to below 10 psi in about 30 seconds.

    Any ideas?
    Last edited: Apr 11, 2010
  2. Thundare

    Thundare Rockstar 100 Posts

    Maybe you should set the timing, idk if it would cause low fuel pressure but it would cause backfires and prolonged starting.
  3. nos351wcm

    nos351wcm Rockstar

    The backfiring could be a timing issue, the fuel pressure drop happened to me in my 2000 1500. had to replace the fuel pump. apparently it is a common problem among the later 1500's.
  4. getawaycars

    getawaycars New Member

    Update: Last Friday the truck wouldn't start again and had to be towed. I had to replace the fuel pump. That fixed the no start issue. However, it still is dropping fuel pressure. It still seems to crank a little longer than expected, but has been running fine so far. I will update again if anything changes.
  5. triple-4x4

    triple-4x4 New Member

    Assuming that your new fuel pump is a good one, I can think of 2 possible problems. Maybe you have a bad fuel pressure regulator and it leaks pressure back to the return line or one of the fuel injectors is leaking. Do you know if anyone has worked on the fuel injectors? Do you have the orig. style injectors or have they been updated. One of the factory service bulletins talks about performing a fuel injection cleaning ( not the stuff you put into the gas tank ) and then if the problem still exists, they start checking the injectors.

    I have a 99 K1500 Suburban (same engine and body style as your 97). To get to the fuel injectors, you have to remove the upper intake plenum. Then you will see what looks like a spider. The fuel injectors are all in one big body, then there are 8 plastic tubes with poppet valves at the end of each that clip into the intake manifold, just above each intake valve.

    The plastic tubes tend to get brittle over time and crack (ie. leak) and then the poppets can get stuck open. It can cost big bucks to fix the orig. system. The dealer was able to look up a replacement unit which came as an entire assembly. The new unit has the injectors placed at the end of larger tubes, so rather than holding them all together and routing the fuel, it sprays like a more modern injector.

    The cost was less than 1/2 of the cost of replacing the orig. style injectors and tubes piece by piece.
  6. getawaycars

    getawaycars New Member

    I replaced the injectors with the aftermarket (upgraded) multiport injectors. I would recommend this to anyone. The truck starts right up, runs great, no more check engine light (due to rich codes) and one mpg improvement. Definetely worth the time and money.
  7. Nolan

    Nolan New Member

    you said you used aftermarket injectors (upgrsded) who did they come from? Napa ,carquest or?
  8. getawaycars

    getawaycars New Member

    Standard Motor Products part number FJ504. You should be able to get this from a non-chain auto parts store.
  9. KonaBurb

    KonaBurb New Member

    did you replace the spider yourself? I see the spider online for around $400. I have access to a good military auto hobby shop and wonder if it's something I could do myself.
  10. getawaycars

    getawaycars New Member


    I have about 8 yrs experience as a mechanic (although it took place in the '80's) and I found it to be a challenging project which took about 6 hours. The most complicated part was disconnecting and labeling everything connected to the upper intake.

    What is a miltary auto hobby shop and your experience level?

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