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What fuel pressure do you run if you have a gauge?

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what is your fuel pressure at idle and WOT multiple choice 211 members have voted

  1. 1. what is your fuel pressure at idle and WOT multiple choice

    • 10-12 idle
      10
    • 13-15 idle
      30
    • 16-18 idle
      50
    • 19-21 idle
      33
    • 22+ idle
      8
    • 10-12 WOT
      21
    • 13-15 WOT
      33
    • 16-18 WOT
      28
    • 19-21 WOT
      4
    • 22+ WOT
      2

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  • Staff

[ATTACH=CONFIG]3634[/ATTACH] Actually its the return line to the filler neck will have all this behind the fitting...

So your saying that spring is not on the Raptor 100 since the return line does not run thru like yours? Is that right. Another question is why I'm seeing sometimes as much as a 5 p.s.i. drop at wot. Would a 60 gallon per hour pre filter cause that? I can change to 90 gal. per hour filter easy enough. BTW, I do have the Vulvan big lines all the way from the big draw straw to the vp. Thanks for opinions too:hyper:

The Raptor has an adjustable regulator for fuel pressue like the ADII does.

  • Staff

Thanks Driply and Mopar I realize, but was wondering too if anyone knew the amount of flow the ISB engine is capable of. Like say 90 gallons per hour. If that's true then I need to go the next filter size up.Also where is that spring and ball on a raptor 100. Don't know how I get so lost and don't understand. I think my head's all bone sometimes:banghead: :)

If I am correct you do not have the spring and ball. The adjustable regulater has a spring and plunger. You adjust your pressure with the screw on the regulator and not by swapping springs like the AD 100 and 150. Just loosen the jam nut and adjust the screw until you achieve the pressure you are looking for. Thats how my ADII works and I would think the Raptor would be the same since it has a regulator.

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    • Like 1

    Im usually 16 at idle, and 15 under WOT. this FASS 95 really moves.

    • Author

    one thing to note, overpressuring will cause leaks and i proved it by accident with my neigbors rig. I installed a raptor150 on his and initially set it at 20 psi mechanical gauge and it ran perfect. I did tell him we need to readjust once the unit breaks in but he told me he was leaking fuel 3 weeks after the install. I tested the pressure and the startup pressure was 35psi!!! idled at 28ish.this was causing fuel to push past the orings/seals on the fuel in water relief drain lever and drip on his axle.i adjusted it back down to 20 psi idle and no more leaking. Plus the small bolts holding that lever to the filter can were a bit loose so i tightened them as well.no more leaks!

    • 5 weeks later...

    You dont reckon the jam nut on the regulator came loose? I set my ADII at twenty and it has settled into 19. over the months.

    • Owner

    one thing to note, overpressuring will cause leaks and i proved it by accident with my neigbors rig. I installed a raptor150 on his and initially set it at 20 psi mechanical gauge and it ran perfect. I did tell him we need to readjust once the unit breaks in but he told me he was leaking fuel 3 weeks after the install. I tested the pressure and the startup pressure was 35psi!!! idled at 28ish. this was causing fuel to push past the orings/seals on the fuel in water relief drain lever and drip on his axle. i adjusted it back down to 20 psi idle and no more leaking. Plus the small bolts holding that lever to the filter can were a bit loose so i tightened them as well. no more leaks!

    Reason why... Because you got to remember the return line is tiny compared to the 1/2" supply line going to the injection pump. So increasing the fuel pressure over 14 PSI will open the overflow valve which is good but excessive pressure will eventually presurize the return line because its too small to handle the return flow. So like with my setup with cold fuel I see 17 PSI @ idle and 15 @ WOT. But with warm fuel its 19 @ idle and 17 @ WOT... Remember I see much colder temps than most of you flat landers...
    • Like 1
    • 2 weeks later...
    • Owner

    I'll admit since I crushed the spring coil slightly to create the oval on the ball end of the AirDog 150 I've had fairly consistent fuel pressure all winter and going into summer. So I'm still holding...Warm fuel19 PSI @ idle and 17 PSI WOTCold Fuel17 PSI @ idle and 15 PSI at WOT

    Hopefully I can vote in this thread next week. :woot:Isspro EV gauge and Glowshift triple pillar are in the mail. Gotta go to NAPA and get the rest of the parts. :thumbup2:

    I have the glow shift triple pod. Its about the only thing good that came out of the deal. Theirs is the cheapest I ever found.

    Yessir, I couldn't believe it! And it's over 25 bucks so it was free shipping. :thumbup2:

    I can affirm Dripley's vote on the Glowshift deal. Cheap is good,,, and that is all I will say about that. I have the Isspro fuel pressure gauge, mechanical with no islolator, well it had the islolator but that whole isolator deal is another thing I am trying to forget about. It has made a nice paper weight on my work bench to remind me how I didn't listen to the M1973Man, Dripley and others on here.

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    • Like 1
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