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Starts then dies.

Discussion in 'Chevy C/K Truck Forum' started by tkbbn, May 19, 2008.

  1. tkbbn

    tkbbn New Member

    99 Z-71 with a 350 5.7. Starts and runs fine and then all of the sudden. Yesterday morning it starts and dies after about 1 second, started it again and same results. It does this several times. After about 30 mins of trying and talking to it a while it started and ran fine. Drove over to the garage turned it off and restarted several times and it was fine. Loaded a few items in and drove about 45miles. Stopped at a store and when I returned same episode as before. After maybe 20 minutes of trying it fired up and ran like a brand new truck again. This time when it wouldn't start I crawled under and could hear the fuel pump coming on and then turning off after a few seconds. Is this a module problem or a fuel pump problem? Any help would be greatly appreciated as the price of these fuel pumps I don't really want to just throw a new one on. Thank You.
  2. MrShorty

    MrShorty Epic Member Staff Member 5+ Years 1000 Posts

    I'm pretty sure your '99 will be similar to my '98. The computer closes the fuel pump relay long enough to get fuel to the engine to start it. After the engine starts, oil pressure is supposed to build up and close the oil pressure switch. the fuel pump is then powered through the oil pressure switch and the computer opens the fuel pump relay. Your symptoms suggest that something is going wrong with the oil pressure switch. Either the engine isn't building up oil pressure or there's an electrical fault in the wiring between the oil pressure switch and the fuel pump.
  3. tkbbn

    tkbbn New Member

    Thanks

    Mr. Shorty thank You for the response, this seems to make sense as I washed it the day before at an automatic car wash and it sprayed the under side pretty well. Probably have a moisture problem in the wiring or a sensor then. It is now 4 days later and no more problems yet but still investigating. If I should find a definate problem I will be sure to post it. Thank You. tkbbn
  4. justinspanier

    justinspanier New Member

    I'm new here, and it's been a while since this thread was last active, but here is my experience with the same problem, for anyone who happens to have this issue. I have a 96 K1500. I drove to the bus station one morning, then drove it home later that day. Got in to drive to the grocery store later that night, went in and got what I needed, but when I came back out, the thing wouldn't start. My wife came and towed me home, and when we got home, it started, but then promptly died. No sputtering...just died. Started it again, and it ran for a few seconds and died. after that it wouldn't start again. I noticed that I didn't hear the fuel pump running when I turned on the ignition, so I checked the fuse panel under the hood, and the fuel pump relay had come VERY loose somehow. I thought back to a couple of days before and remembered a huge dip that surprised me. I think that the speedbumps in the grocery store parking lot didn't do it any good either. I pulled it out (actually it kind of just popped out) and re-seated it...WHALLAA!! I haven't had it happen again since. It's been several months now. I hope someone finds this helpfull.

    Justin
  5. justinspanier

    justinspanier New Member

    Just an update. This silly problem kept happening every once in a while...not that it is a big deal, since I knew how to make the truck start(as above). I finally decided to figure it out when the truck wouldn't start at sonic after going out for a burger. I got it started, but it is kind of embarassing to have to pop the hood, open the fuse panel, re-seat the relay, then start the truck. everybody was looking at me like I was a hick or something!! I got to looking to see why I kept having to re-seat the silly fuel pump relay, and found that one of the connectors inside the fuse panel was bent, making it easier for the relay to loose contact with the fuse panel. I took a little screwdriver and bent it back out to where it should be, and so far haven't had to re-seat it yet.
    Last edited: Apr 21, 2009
  6. Springthing

    Springthing Epic Member 5+ Years 1000 Posts

    Muahahah! Love it..!..

    Thanks for the information. I'm sure this will come in handy to others in the future.

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