Will advancing the timing on my TBI engine help?

Discussion in 'GM Powertrain' started by Crawdaddy, May 21, 2013.

  1. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    So I'm about to change the distributor on my 91 Suburban with the 5.7L TBI engine. I've also been wanting to put a hotter coil on along with quality cap, rotor, and wires. I would then gap the plugs wider and bump the timing earlier in an effort to get a little more power and ,more importantly, get more MPGs. I got to thinking about it, and I'm wondering if bumping the timing is actually going to have an effect because of the timing being at least partially controlled by the computer. Will the computer retard the timing to compensate for the advancing I did? Or, does the computer-controlled ignition just start from the base timing I set and advance only from there?
  2. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    On another forum I posted this question on(ford forum), the response has been that I can't advance the timing without making it run bad because the TBI can't deal with the timing being that far out of spec. Any opinions on that?
  3. offroadmaine

    offroadmaine New Member

    you truck has an electronic spark control(esp) when i built a motor for my 93 i had to retard the timing from the factory specs and when i did my research on almost the same question what i came up with is that you have to set the timing with the esp unplugged (cant remeber if the truck HAD to be running or not but i always adjust the timing with it running) then you will disconnect your battery for 15 min to reset everything plug your esp back in an the truck will adjust from the timing you have started it at. this is what i did and it worked fine for me.

    the esp is located under the wire cover on the passerger side under your hood (the peice of plastic that looks like a capital T with a big wire juntion underneath it. it is a brown bout 2-3 inch long kind round plug

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