98 Blazer will not start, have troubleshot best I can already.

Discussion in 'Chevy Truck Forum' started by 98blazer, Aug 12, 2011.

  1. 98blazer

    98blazer New Member

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    Hello all, New to this forum. I just bought ($100) a 98 Blazer with 208k miles, which will not start 98% of the time on it's own unless you pour gas into the throttle body. I have gone through the sticky on this site and have done all the checks I can considering I do not have a scanner. After it starts with the gas poured in the engine revs well if the pedal is slowly depressed. If you jump on the throttle it stumbles badly the slowly works its way up to about 4000 rpms. No trouble codes or check engine light. All fluid levels are on full.

    Here is where I stand: 1. I changed the fuel filter and hooked up a pressure gauge. mid 40's as soon as you turn the key on and does not go down. The pressure once it starts is mid to high 50's and stays steady. 2. I cleaned the MAF sensor and at first it started better, but then it went back to not starting. I replaced the MAF and it made no difference. 3. Just had a Cadillac that would not start and the fix was to change the crankshaft position sensor. I changed the crankshaft position sensor but no change. 4. Checked ignition wires for spark while cranking and had strong spark.

    PLEASE HELP!!!


    Thanks, Andy in Kentucky
     
  2. dirtrider73068

    dirtrider73068 Moderator Staff Member

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    My ex wife has a 01 blazer had this same issue except hers would not start and had spark fuel pressure, and turned out to be something with the MAP sensor. I would also check all your connections, grounds, make sure no wire is cut or been shorting out anywhere.
     
  3. chevychase

    chevychase Senior Moderator Staff Member

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    Your getting no codes... pressure in mid 50,s you need at least 60 for it to run right... if off by a few psi will cause problems.
    Most times if no codes will be fuel related.
     
  4. MikeG

    MikeG Full Member

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    Another easy check; put a timming light on it to make sure it's not off.
     
  5. twinstroke

    twinstroke Member

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    also another point of interest is the catalytic converter is it clogged this can creat problems and often time over looked i have expierenced these systems from a car and replaced the catalytic converter. converter clogged to much back pressure chokes motor down and slowly accelerates. and yes acted like it was starving for fuel. when it was actually getting enough. but couldnt breath so had to keep fueling it more till it fired and didnt last long. and no codes could maybe light don't work.


    another place to look is the EGR valve My wifes 2000 trail blazer did the same thing but fuel pressure a little better the EGR was sticking open and not closing due to carbon build up. Also got no codes for it either. replaced EGR and she ran like a top.
     
    Last edited: Aug 13, 2011
  6. 98blazer

    98blazer New Member

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    Thanks for the replies, I will check it out and repost.
     

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