Timing a 97 Silverado 5.7

Discussion in 'General Chevy & GM Tech Questions' started by libby2159, Dec 23, 2010.

  1. libby2159

    libby2159 New Member

    Really, you have to have a 97 timed via a computer/scanner? What ever happened to the nice timing light that everyone could afford? I think the dealership/parts store, along with my husband are full of hooey that that ONLY way to time a 1997 1500 series Silverado 5.7 350 is with the scanner/computer hook up and then the truck's computer times itself once you are 0 (+/-). What year did this start and when does it end??!!!!!
     
  2. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    it started in 1996 and in 1999 they went to a differnt design that doesnt use a distributor. But yes the 4.3L V-6 5.0L V-8 and the 5.7L V-8 have to be timed this way.
     
  3. wis bang

    wis bang Rockstar 100 Posts

    It started with computers! The OBD I system that came in the 86 S-10, and others, still allowed you to use a timing light BUT you had to disconnect the computer first. You couldn't see the timing mark if you failed to pull the computer's plug...

    Then the Feds decided that OBD I was too easy for hackers to over ride and the pushed the auto makers to make things more difficult and OBD II was born.
     
    Last edited: Dec 23, 2010
  4. libby2159

    libby2159 New Member

    It's just ridiculous! I realize things are supposed to improve through the years, but lemme tell ya, I had a 1990 1500 series Chevy and I could EASILY get 20mpg on the highway, about 15 in the city - give or take. The truck had around 250,000 when I sold it and bout my 97. What a mistake. I should have stuck it out with the little bit of rust the 90 had and one or 2 wiring gremlins vs what I am going through with my 97. We waited about 2 days to get the timing done after the intake and heads were done, etc, and that was the BEST mileage I got, there was a little bit of a spark knock but she started, she ran, just lacked her giddy up. Once it was timed, a tank of gas later, I got 10 MPG!!!!! So, it is going back in to be timed again but that is not right - I was getting at least 14 on the highway. But really, shouldn't it be doing better than what my 90 was? Just silly. I read somewhere that on the 97 you could time it without a scanner by disconnecting the ECM wire, but sounded too risky for me just to wing it!
     
  5. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    Nope that is why i said the 1996 up had to be timed with a scanner period.. But it sounds like the shop didnt actually get it to 0 degrees TDC. before they used the scanner.
    as to the milage, it all depends on the differences between the model ie: gear ratio etc etc.. but 14mpg is to low to begin with.
     

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