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Can't seem to get the right fuel pressure

Discussion in 'HYBRID -> EG-EK / DC' started by 99sidude, Apr 27, 2008.

  1. 99sidude

    99sidude Moderator Moderator VIP

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    For some reason my car is running way too much fuel pressure (I'm seeing 60 psi and stock is 40). I have a Walbro 190lph pump feeding a stock gsr fuel rail and stock fuel pressure regulator. At idle and part throttle the car runs super rich (won't even register on wideband gauge) and has trouble iding smoothly.

    I figured that the pump provided too much volume for the stock regulator to handle, so I replaced it with an AEM adjustable one. With that I am only able to reduce the pressure to ~50 psi. After doing some reading I found out that people are running up to a 255lph pump on the stock reg, so I looked if there was a kink in the return line. Nothing.

    Today I tried to tune the fuel pressure by venting the return line strait off the regulator into a gas can (hence eliminating any potential line blockage). I am still seeing way too much pressure (no difference from before). What could be causing this?

    w00t 1000th post
     
  2. t3t4delsol

    t3t4delsol New Member

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    any cel codes? A bad o2 sensor can make you run rich
     
  3. 99sidude

    99sidude Moderator Moderator VIP

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    No cel's and a bad o2 won't make you run too much fuel pressure. I need to know what would be causing this high pressure.
     
  4. t3t4delsol

    t3t4delsol New Member

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    I'm just throwing this out there because I have no clue unless your tune is off, have you changed the fuel filter lately, If you have something clogging your fuel lines its possible that the pressure could increase
     
  5. 99sidude

    99sidude Moderator Moderator VIP

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    Well I am measuring the pressure in the fuel rail which is after the fuel filter... Any other ideas out there? Blanco I know you have something to add.
     
  6. b16stalyun

    b16stalyun New Member

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    wouldnt that make it decrease? at least when i had the same problem my car would die randomly for a second then start back
     
  7. t3t4delsol

    t3t4delsol New Member

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    with the stock fuel pump it probably would decrease, hes uses a walbro which if something was blocking the lines the walbro should have enough shit in it to increase the pressure, to compensate for the loss in space
     
  8. t3t4delsol

    t3t4delsol New Member

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    however I dont think thats his problem, hes got me stumped, try a different adjustable fuel pressure reg, one that has more adjustment
     
    Last edited: May 1, 2008
  9. 99sidude

    99sidude Moderator Moderator VIP

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    Its an AEM one thats suposedly good to 1000 hp. Not only that, people are running stock regulators with the same setup as me with no problems. I am stumped as well
     
  10. nootrac22

    nootrac22 Well-Known Member VIP

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    I would start by checking the PSI out of the pump. That sounds like the problem, with that much variance.
     
  11. 99sidude

    99sidude Moderator Moderator VIP

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    That's an idea. Its not really the psi it's more the flow rate. Its rated at 190lph. I've heard of people running a 255lph on stock honda fuel systems no problem. I highly doubt mine is pushing out even more than that. Never know tho...
     
  12. nootrac22

    nootrac22 Well-Known Member VIP

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    The classes I had in trouble shooting alway taught the same thing, but it was in electronics. Start with the most simple. TVs were used in our example step 1 is the tv pluged in step 2 is the tv on step 3 does the tv have a signal. So here your the initial steps are eliminated the car starts and gets fuel, but too much. Now the next steps are where does the problem originate? Thats the pump. Start there and follow down stream. I would start by checking the electric to the pump, make sure it's getting the proper voltage, inturn eliminating any electrical causes. If that is eliminated (electircal) the only thing left is physical.
     
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