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Engine probs...

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Trigger, May 18, 2003.

  1. Trigger

    Trigger Registered Member

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    The idle is way too high and after its warmed up sometimes it wont even hold idle and it wont start back up if it dies. I have replaced vacuum lines, coolant sensor, O2 sensor, MAP sensor, rotor, cap, and plugs. It blows out dark smoke when you give it gas but at idle it blows out whiteish/gray smoke. I just bought a TBI from someone and going to put that on to see if the TBI is bad, if not I will take the old one to a friend and have him bore it out for more air intake. /forums/images/graemlins/laugh.gif What do you all think the problem could be? Don't have a timing gun so I haven't checked that yet but with it's hesitation at throttle makes me wonder if timing is off a little. I'm sorry to bother you guys so much but I've done just about everything everyone has said and still not running right. /forums/images/graemlins/1zhelp.gif
     
  2. JustHorsinArownd

    JustHorsinArownd Registered Member

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    This may be of no help but... It sounds to me like you're running way to rich almost like when a choke sticks. Maybe this can clue someone else who knows lots about TBI's to have a brainstorm. Hope this helps. Good luck!

    Allan
     
  3. bryguy00b

    bryguy00b 3/4 ton status

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    whitish grey smoke at idle..that seems like how my 84 k5's 305 runs..idles really high and smokes white smoke like a friaght train..might have a bad head gasket. that can be coolant leaking in and getting burnt. just a thought
     
  4. Big Red

    Big Red 1/2 ton status

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    My truck used to smoke like a freight train too. But my problem was bad rings. But she would hold idle. Though a few times she would stall and not wanna start. or she would and then die again.
     
  5. Thunder

    Thunder 3/4 ton status

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    Have you checked for trouble codes
    Did anything come up?
     
  6. Big Red

    Big Red 1/2 ton status

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    nope, nadda. which is strange cus you think the dang ecu would pick up on the fact that theres no compression and its having to work harder to motivate the dang truck. /forums/images/graemlins/grin.gif /forums/images/graemlins/k5.gif
     
  7. bee32

    bee32 1/2 ton status

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    Sounds like lose of compression. Rings or head gasket. /forums/images/graemlins/ignore.gif
     
  8. MousePowrd

    MousePowrd 1/2 ton status

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    Do a compression test, only takes 10 min. See if all the cylinders have even compression, or if one or two are low
     
  9. foxman

    foxman 1/2 ton status

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    which coolant sensor did you replace, the one in the cylinder head or the one in the intake? The one in the head only controls the guage, the "2 pronger" in the intake controols engine computer signal. if you replaced the one in the intake and no codes then the best possible scenario is a defective replacement sensor or hidden voltage drop. To monotor this you have to have access to a scan tool. The local auto parts store usually rents them out for free. (murrays, Autozone)(usually a couple hunderd dollar deposit) anyway, don't just get the code flasher, this will tell you only if the computer has encountered a default code. I recommend the Actron brand scan tool. It has a 3 line display readout. After pluging the scanner in, you can choose an option to "view stored codes" or to "view Data" <--or something like that. You can monitor what is happening with the engine running by scrolling through the sensors and viewing their respective voltages. Only when the sensor drops below a certain voltage will it store a code or even set the "Check Engine" light off. This does not mean that the voltage the sensor is givig off is correct... There is a manual with the scan tool software, and it lists off typical voltages and the definitions for each abbreviated sensor listed.

    I found a bad TPS just by comparing the typical voltage listed in the book to mine. and it didn't set the check engine light off.

    Pay specific attention to your engine temp line when monotoring the list with the engine running, this should for sure find your problem.

    My 90 k5 with 190,000 smokes like crazy. It burns oil, coolant and sometimes gas!!!, it has never stalled on me though, unless an electronic sensor was bad.

    Good luck.

    Jeremy /forums/images/graemlins/usaflag.gif
     

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