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Timing issue on a 1994 350 TBI

Discussion in 'GM Powertrain' started by Ethan, Apr 4, 2012.

  1. Ethan

    Ethan Rockstar 100 Posts

    I recently did a intake manifold gasket on my truck, and have been trying to get the timing right, but a few things are striking me as odd. First off, I have access to a GM Tech 2 with an OBD 1 connector, so I can see what the computer is trying to do to my timing as I drive. Secondly, the timing tab above my harmonic balancer is all scratched up, so I can't tell where 0 degrees is, so I'm guessing at this point. Originally I put it where it's below the 3 smaller bumps, but inbetween the large last bump. When it was set there, at idle my timing was advanced by 20 degrees constantly, and even if I accelerated, it would stay 20 degrees advanced. So I retarded the timing by 5 degrees, or 1 notch on the timing tab. Now its still idling at 20 degrees advanced, but when I accelerate it retards to 2 degrees advanced.

    I do disconnect the brown with black strip wire under the dash when I time the engine, just in case ya'll wondering. I'm very confused since I know most vehicles will idle at 10 degrees advanced and under acceleration advance to 20 degrees. Since it's staying at 20 degrees advanced, a explanation would be nice, or a way to solve this problem, if it's a problem.
  2. dualdj1

    dualdj1 Rockstar 100 Posts

    have you watched what it does with the wire connected vs disconnected? have you verified with a light that it's advancing, not just relying on the information from the computer?

    I believe base timing should be like 4-6 degrees advance. don't remember off the top of my head. Your best bet is to get an adjustable timing light so you can just work off of your 0 mark.

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