Chevy 350 TBI Timing issues, Please Help!

Discussion in 'Chevy C/K Truck Forum' started by mace1530, Dec 2, 2011.

  1. dipstick

    dipstick Member 2 Years 100 Posts

    I think the ecm is adjusting all it can for the cam you have. When you disconnect wire putting in limp mode.
  2. mace1530

    mace1530 New Member

    Thanks for all the advice! i am still having the same issues, and have advanced the timing (tan wire disconnected) up to about 16 btdc. I have Not replaced the distributer i said, runs like a champ with esc(tan wire ) disconnected, but can this cause any longterm negative effects?damage to anything?
  3. ejohnson03

    ejohnson03 Epic Member 5+ Years 1000 Posts

    So you have road tested it with the wire disconnected?

    Don't know of any issues... if it works then great.
  4. mace1530

    mace1530 New Member

    Road tested today actually, seems to run fine with the esc disconnected. still havent replaced the distributer as you suggested, that will be an "after Christmas Project", Lol. Thanks for Your advice ejohnson03!
    Happy Holidays
  5. mace1530

    mace1530 New Member

    Okay folks, Merry belated Christmas, and Happy New Year.
    So, I have beeen driving sparingly, and have put about 200 miles on the motor, with the esc unplugged. As of yesterday(and I started a new job today) the truck started acting uP. Normally it starts up as soon as I turn the key, but fired once, and died immediately. I had not started it in 4 days, so I turned the key back off(to reprime the tbi) and tried again. no luck, and i smelled gas, so I held it to the floor, and it fired right up, but blew black smoke, smelling like gas(of course, I think I unintentionally flooded it). However, it has not run right since. It appears to be "loading up in the carb"(throttle body, but you get the idea), or the spark cannot keep up with the amount of fuel.
    The body has 92,000 original miles, and it is a Rhode Island truck(sat by the ocean, and I am in central Ohio), and as my original post states, Everything in the internal engine and heads are brand new, proffessionally machined, balanced, and bored.
    Any thoughts would be Greatly Appreciated, Folks!!!

    ---------- Post added at 08:53 PM ---------- Previous post was at 08:40 PM ----------

    If I set the distributer in a toothe or 2 off, could this be a contributing factor? I'm sure I din't, but am second guessing myself now...Scott and ejohnson03 have my "wheels turning," Lol! I think I will just replace everything ejohnson03 reccomended, but still, any thoughts would be grea!
  6. outalne94z71

    outalne94z71 Member

    i bet you have way too much cam for the map sensor and ecm to handle, contact tbichips, they can get you setup better for what you are doing
  7. mace1530

    mace1530 New Member

    Thanks, and you could be right, but i purchased it at Jegs, and according to the book, and saleman, this is the biggest cam I could go without modifying anything(but I am not ruling out what you said). How can I check ouyour theory?
  8. outalne94z71

    outalne94z71 Member

    send a message to or call the contact at tbichips and discuss your issue and what cam specs you have along with any other mods and they should be able to tell you exactly if your cam will play nice or if you need a custom chip to deal with problems like too much lobe separation causing low vacuum or whatever issue you may be having.
  9. mace1530

    mace1530 New Member

    ok long time later, i figured it out! bad distributer, and intake air temp control sensor, caused the idle to lope. Running Great!
  10. ishkish

    ishkish New Member

    I have a 1990 5.7l suburban. I was having all sorts of issues when I bought is as the third owner.
    O deg tdc with the esc disconnected and at norm operating temp. The timing chain all new and sprockets? If not make sure the button on the distributor turns immediately when you jog it via the crank snout or dampener bolt. After that, go after the brain. Vacuum on a tight engine is 18-22 inhg. If you have a vacuum ga on the unit and rev it and the ga drops but is very slow to recover now you are talking timing issues with the valve train, not the timing with the light. Hope this points you good direction.

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