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many cranks to start

Discussion in 'The Garage' started by mtrdrms, Mar 29, 2005.

  1. mtrdrms

    mtrdrms 1/2 ton status

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    I have an 87 350 FI. I just had the motor rebuilt but that didnt affect my problem. Whether it is hot or cold the truck takes like 2 seconds of cranking to finally start running on its own. Its a little embarrasing and I cant seem to make it go away. Any suggestions? Other than that the motor is tip-top.
     
  2. k20

    k20 3/4 ton status

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    2 seconds isnt that long lol. Is it cranking over at a good speed? Is it sluggish turning over, like a weak batt, or batt cables? Also, is the fuel system pressurizing when u switch the key to on, b4 you turn it to start?
     
  3. 75-K5

    75-K5 3/4 ton status

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    That's just how TBI motors work.
     
  4. clarkjw24

    clarkjw24 1/2 ton status GMOTM Winner

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    Maybe timming? How about the air idle sensor, its like the choke but takes a few seconds to read and set for cranking. :xmas:
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    I'm with you on the fuel pressure.

    Do you hear the pump run when the key is turned to "run", before you start the engine?
     
  6. BigOrange90Jimmy

    BigOrange90Jimmy 1/2 ton status Premium Member

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    Don't the oil pressure sending units have something to do with start-up? I believe I heard that it won't let the engine fire until it senses enough oil pressure.
     
  7. 1979jimmy350

    1979jimmy350 1/2 ton status

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    on the tbi engines if the the fuel relay fails the fuel pump will not kick in until the oil pressure sensor reads 4 psi of pressure usually resulting in longer than normal cranking times
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    Yeah, as stated, if relay fails, oil pressure is what will "start" the fuel pump.

    Thus, if the pump doesn't prime when key is turned to run, the relay is suspect.
     
    Last edited: Mar 30, 2005
  9. clarkjw24

    clarkjw24 1/2 ton status GMOTM Winner

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    Yep, I believe we have a winner. :xmas: I'm voting fuel relay also.
     
  10. mtrdrms

    mtrdrms 1/2 ton status

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    The pump sounds like it is priming the system. I can hear it anyway. What is the fuel relay and how do I test it?
     
  11. 87XJCO

    87XJCO Newbie

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    suggestion. turn the key to on for 2 seconds and then turn off. then crank engine nomally and see if it starts right up. This runs the fuel pump briefly and the injectors cycle once. Might eliminate some of you r possible causes.
     

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