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Fuel Pressure Problem! Any Ideas

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Old 09-08-2005 | 11:07 PM
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FikseRxSeven's Avatar
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so... i cant get my fuel pressure lower than 62psi at 12v and cant get it lower than 69psi when the car is running and im getting 14v





the story.



i noticed that my fuel system was not holding pressure when the car is off, and i wasnt getting proper fuel pressure. so i decide to check out the tank. found that i had a crack in one of the lines, replaced both of them with high pressure fuel hoses (easy enough). now when i turned the car on, my fuel pressure skyrocketted!!!! i had to get to work soon, so i let the car run for 15 mins to make sure everythign will be fine, and everything was fine til then.



when i got to work, i noticed a fuel smell and then saw gas dripping from around the firewall/transmission area. so went into work and let things cool down. when i left work, i checked the pressure from just the battery, and it was still at 62psi. i then screwed the FPR adjuster in, and as the fuel pressure hit 70psi, i hear a hissing sound and fuel started dripping again. i then lowered the fuel pressure and it stopped.



to make the drive home, i disconnected the power to 1 of the fuel pumps. with 1 walbro 255, my fuel pressure was good at 40psi. drove home with no gas smell.



i have yet to determine whether the leak is coming from the feed side or the return side of the fuel pressure regulator, judging by the location of the dripping fuel, its the return line,



my setup right now are 2 fuel pumps, each feeding the primary and secondary rails, the lines meet at an FPR and returns to the stock return line. so 3/8" hoses(and metal lines) and -6an lines and fittings from the firewall. right now i have an xs fpr on there, im gunna try another fpr to rule that out.



just on a side note... rfreeman is running the same setup and is getting 40psi.



martin
Old 09-08-2005 | 11:11 PM
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phinsup's Avatar
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fpr **** maybe?
Old 09-08-2005 | 11:21 PM
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Take a look at the fuel pulsation dampener too. I had one go bad and leak fuel.
Old 09-08-2005 | 11:31 PM
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i dont have a fuel pulsation dampener, both my primary and secondary rails are aftermarket with topfeed injectors.... maybe bad o rings? ill have to check tomorrow
Old 09-09-2005 | 01:33 AM
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a thought came to my mind.... what if any of the emissions stuff was accdentally forgotten by the tank... i assume that would cause a restriction right?



i remember seeing something that resembled a check valve (white with green) around the fuel tank area when i openned it up earlier
Old 09-09-2005 | 10:28 AM
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Usually not a problem, what pump and regulator are you running?



Chris@gtgarage.com





[quote name='FikseRxSeven' date='Sep 8 2005, 11:33 PM']a thought came to my mind.... what if any of the emissions stuff was accdentally forgotten by the tank... i assume that would cause a restriction right?



i remember seeing something that resembled a check valve (white with green) around the fuel tank area when i openned it up earlier

[snapback]756690[/snapback]

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Old 09-09-2005 | 01:21 PM
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i have 2 walbro 255lph and an xs engineering regulator
Old 09-09-2005 | 05:32 PM
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get another regulator. Verify that your return line goes straight back into the tank withno kinks.
Old 09-11-2005 | 09:55 AM
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sounds like restriction in the return line ^^^^^^^^^^^
Old 09-11-2005 | 09:55 AM
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Its the Walbro pump they are unreliabl, noisy, and have drain back problems , Use OEM twin turbo supra pump, Itl supply min. enough for about 450 wheel hp









[quote name='rfreeman27' date='Sep 9 2005, 03:32 PM']get another regulator. Verify that your return line goes straight back into the tank withno kinks.

[snapback]756961[/snapback]

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