your thoughts please

Discussion in '1994 - 1995 Specific Tech' started by BlackVert, Oct 26, 2004.


  1. BlackVert

    BlackVert Mustang Master

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    i recently installed a used stock fuel pressure regulator. i have the stock maf back in. and i have stock injectors.

    i set my high and low slopes back to stock (28.8/19.64). the kamrfs were around 1.15. i have lowered them both gradually. the high slope is now 17, low is 26. it is still lean, but not as lean.

    i am thinking it must be one of:

    (1) fpr is bad
    (2) fpr was dirty or rusty, injectors and/or fuel filter are now clogged
    (3) vacuum tube from intake to fpr is not very tight, not enough vacuum

    any other thoughts?
    #1
  2. BlackVert

    BlackVert Mustang Master

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  3. mytight95

    mytight95 Active Member

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    the reg is good........i assume you changed the values with the tweecer or something.........

    :shrug:.........

    only thing i can think of is if the car has mods.......you may need more pressure....PUMP.........or that the filter is clogged.......pump could be going bad....................hey man e-mail me what it is doing....[email protected].........are you checking the pressure with the vacuum off..............


    jason
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  4. BlackVert

    BlackVert Mustang Master

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    ever run out of gas? it acts like it is on the verge of running out of gas.
    it was much worse on the way home.

    - i believe that the fpr is not bad
    - yes i changed the values with my tweecer.
    - my mods are not nearly extensive enough that there is no possible way i am maxxing out the injectors. the highest duty cycle i have seen is like 15%.
    - could be the pump - good point
    - i need to dig up my fuel pressure gauge and hook it up.
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  5. mytight95

    mytight95 Active Member

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    yeah i would do that.............with the gauge............i would guess that the pump is going bad or the filter is clogged if you are only seeing 15% duty cycle...................


    you need to check the pressure.......check the filter etc. i think.................try and run it without vacuum on the reg.........block off the vacuum line from the intake.......drive it.........see how it does..............





    jason
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  6. BlackVert

    BlackVert Mustang Master

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    stupid question time: will taking the vac line off increase the pressure or decrease it?
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  7. BlackVert

    BlackVert Mustang Master

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    ok, i got the answer to this one: the pressure will go up.

    another question: after replacing the fpr, do you need to do anything to get the air out of the fuel lines?
    #7
  8. HISSIN50

    HISSIN50 "How long does it take to get help in here? SN Certified Technician

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    prime the pump. :D

    the system flows enough pressure to purge the system of air (unlike old low pressure mech pumps).

    good luck.
    #8

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