| Go back to previous topic | | Forum name | Turbo/Nitrous Tech | | Topic subject | Fuel Pressure goes DOWN per pound of boost...WTF! | | Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=77073 |
77073, Fuel Pressure goes DOWN per pound of boost...WTF! Posted by xtrickedeclipsex, Sep-28-04 06:56 AM
Well, I have been thinking all night about WTF the cause of this problem…I have my 1:1 reg, now as we no, I should have my static FP around 43-44 pounds, and every pound of boost I get, my FP should raise a pound…Now in my situation, the EXACT opposite happens under boost, my 45 pounds of FP goes DOWN per pound of boost…WTF!?, so I start to lean out big time. I had a hole in the vac line going to the Aromotive 1:1 reg, I changed that vac line today, then i drive the car and noticed this shit…But I triple checked, all my lines are hooked up correctly, or so I can see….any ideas?
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 "Oh yea, well...My manifold does cool twisty things"
www.EnhancedMotorSports.com
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77077, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by davo345, Sep-28-04 06:56 AM
you run the MS, no? check your values. Also check your fuel lines. And another alternative is that your FPR is busted.
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77089, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by turbo8u, Sep-28-04 06:14 AM
Originally posted by davo345 Also check your fuel lines.
heheh....:order....
tank----> pump-----> rail----> reg----> tank
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77097, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by xtrickedeclipsex, Sep-28-04 08:42 AM
arg...im going nuts...anyone? ---------------------------------------
 "Oh yea, well...My manifold does cool twisty things"
www.EnhancedMotorSports.com
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77111, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by Eclipse2NR, Sep-28-04 11:47 AM
Post a little more info on your regulator, the fittings (as well as inputs and outputs). I know some of the Aeromotive regulators have an in (from pump), an out (to rail), and the return (to tank). Thats different from the SFMU. Also post what lines are going where. Where exactly is your fp gauge hooked up?
Little more info please.
1996 Eclipse RS / 5-Speed / Aerogear Body / Coated in Magnetic Red Metallic rev.2 / T3 Turbo Intercooled @ 8 psi / http://www.team2nr.com Mark Galyan - Indianapolis, Indiana
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77119, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by XtremeRS, Sep-28-04 12:39 PM
What kind of fuel pump do you have? I had my accell inline pump off my car for a few days, and tried boosting only like 5 psi..fuel pressure would go up, then go right back down because there was not enough flow out of the stock pump...Check all your lines, and be SURE you have a good, leak free boost signal at the FPR.
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77128, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by xtrickedeclipsex, Sep-28-04 01:56 PM
Originally posted by XtremeRS What kind of fuel pump do you have? I had my accell inline pump off my car for a few days, and tried boosting only like 5 psi..fuel pressure would go up, then go right back down because there was not enough flow out of the stock pump...Check all your lines, and be SURE you have a good, leak free boost signal at the FPR.
I have a NOS inline fuel pump - same as the accell inline pump...and a stock intank pump. So once you started to build boost, the fuel pressure dropped? That’s exactly what happening to me...I have the auto meter gauge, inside the car, it’s NOT mechanical. The sending unit shit is ON the Aromotive 1:1. My fuel set up worked how its set up for a couple weeks, so I no its nothing we hooked up wrong…Its something that recently happened. If my inline wasent getting power, woudl that cause the FP to drop?
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 "Oh yea, well...My manifold does cool twisty things"
www.EnhancedMotorSports.com
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77129, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by turbo8u, Sep-28-04 01:59 PM
how's your inline hooked up? on the 12v relay for the stock pump or what?
just re-do the lines doodlet, theyre kinda :nuts anyway, im surpised you didnt run lean as hell already
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77130, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by xtrickedeclipsex, Sep-28-04 02:02 PM
Originally posted by turbo8u how's your inline hooked up? on the 12v relay for the stock pump or what? just re-do the lines doodlet, theyre kinda :nuts anyway, im surpised you didnt run lean as hell already
I think we did it on the stock relay, not sure. I think I didn’t go that lean because the mega squirt is not sooooooooo needy of fuel pressure..
the line is not leaking going to the fmu, thats what i replaced in the first place, the vac line going to the fmu, had a hole
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 "Oh yea, well...My manifold does cool twisty things"
www.EnhancedMotorSports.com
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77146, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by xtrickedeclipsex, Sep-28-04 04:42 PM
:scratch ---------------------------------------
 "Oh yea, well...My manifold does cool twisty things"
www.EnhancedMotorSports.com
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77153, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by MetalJim, Sep-28-04 07:23 PM
So when you're sitting there idling the fuel pressure is about 33-35 right? And when you step on the gas it works its way up to 43 right? I understand the part about when you hit boost that it starts dropping back down, I just want to make sure of this other stuff - the non-boosted stuff.
 95 Eclipse RS : 5 speed 15.7 @ 87.9mph Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html
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77154, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by xtrickedeclipsex, Sep-28-04 07:40 PM
Well, I have always had high high high fuel pressure, at IDLE with vac im hitting like 45...Its high, and I no why...but it worked perfectly fine like that for a while.
Now, it wont move up or down at all under vac,Once I hit like 10-15 pounds, and it starts to move pretty fast down into the low 40's and high 30's....im so stumped
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 "Oh yea, well...My manifold does cool twisty things"
www.EnhancedMotorSports.com
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77174, RE: Fuel Pressure goes DOWN per pound of boost...WTF! Posted by thedawg, Sep-29-04 06:51 AM
The stock wiring and relay can't handle both the stock and an inline fuel pump. Give the inline its own direct 12v power source and its own relay. In fact, you should be giving the stock fuel pump its own direct 12v power source too.
Search for "fuel pump rewire mod" or something.
I think your fuel pumps can't keep up with your injectors at the higer flow rates.
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