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  #11  
Old 08-25-2018, 02:29 PM
dhutton dhutton is offline
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Pretty sure that pump is cooking your fuel if the external temperature is 175 degrees. What is the temperature of the fuel lines connections in and out of the pump? If the output side is much higher than the input side then that would show it is heating the fuel...

Don
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  #12  
Old 08-25-2018, 02:41 PM
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Just copied off the internet -- not my personal knowledge -- but trying to find something helpful.



Gas doesn't typically "boil", but it does vaporize (evaporate) at anything over 93 degrees F or so. As I understand it, the "boiling point" of regular 87 unleaded is about 181 degrees...but this will differ depending on pressure and what additives are in the gas
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Old 08-25-2018, 04:21 PM
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Iíll check the line temps. But dam, is this normal for this pump? Iíve got it lower than the tank like Aeromotive said and all the lines are well insulated past the header collector.
Letís say I use an in tank pump without changing anything. About how cooler would the fuel be? Iíve got some lava header wrap coming in the meantime. Itís more of a do it yourself shield like you see on LS motors. Trial and error I guess. Thanks for all the help.
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  #14  
Old 08-25-2018, 04:34 PM
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I don't need an answer -- I'm just THINKING OUT LOUD --- so to speak.


Fuel "boils" when under vacuum (suction) --- so since the pump is external to the tank and pick up --- What size is the pick up tube?? And do you have any sharp 90's on the INLET side from tank to pump.... I try to use 90* "sweeps" instead of hard 90's or GO UP IN SIZE on the pick up and plumbing to the pump to avoid that. IDK.
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Old 08-25-2018, 05:02 PM
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-10 sending and -8 return. The fittings are both at a 45 degree coming from and to the tank. The sending line makes a nice radius above my rear axle, goes around to the side next to the frame rail where the pump is mounted. Just behind the rear tire and under the trunk floor. I have a pre filter, then the pump then the line does a 180 (2 90 degree fittings joined together) to another filter then itís a straight shot to the fuel rails.
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  #16  
Old 08-25-2018, 05:13 PM
dhutton dhutton is offline
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Quote:
Originally Posted by J-440 View Post
Iíll check the line temps. But dam, is this normal for this pump? Iíve got it lower than the tank like Aeromotive said and all the lines are well insulated past the header collector.
Letís say I use an in tank pump without changing anything. About how cooler would the fuel be? Iíve got some lava header wrap coming in the meantime. Itís more of a do it yourself shield like you see on LS motors. Trial and error I guess. Thanks for all the help.
Depends on the pump you use and how you control it. Iíve used several Vaporworx controllers without a hitch. The beauty is the pump never runs any harder than it needs to. Keeps heat to an absolute minimum. No return line to mess with.

Interested to see those input and output fitting temperatures.

Don
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  #17  
Old 08-25-2018, 08:17 PM
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I might suspect the 180* -- maybe try rerouting that temporarily to see if the issue continues?? IDK -- we're just trying - at this point - to find ANYTHING....
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  #18  
Old 08-25-2018, 08:25 PM
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I ďassumedĒ that efi wouldnít allow a vapor lock to happen. Iíve seen guys run fuel lines in some stupid places, like right beside headers and turbos, without a hitch.
What does your fuel pressure gauge say when this happens? Maybe try and pop the orifice at the fuel rail to see if thereís fuel pressure there when this is going on, regardless of what gauge says. Heat is your enemy when it comes to fuel systems, especially with an inline pump setup.
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  #19  
Old 08-26-2018, 09:47 AM
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When the car starts to die, the fuel pump starts cutting in and out then it dies. My regulator is at 0 psi. Iíll wait 10 minutes, pressure is back up to 59psi then the car fires up. Gonna get those line temps here in soon.
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  #20  
Old 08-27-2018, 12:00 AM
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Zspoiler Zspoiler is offline
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Have you tried a heat shield under the fuel injection?
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