Fuel Heating Problem.....questions

Discussion in '1996 - 2004 SN95 Mustang -General/Talk-' started by vertigasen, Jul 7, 2014.

  1. I am back in the country for, well, at least a little while. I am hoping I don't deploy again for the next year or so. Onto the car......

    It is running great. Short trips, no issues. On hot days, 30 mile trips and I can watch my fuel pressure drop as I am driving. It will dip down to about 38-37, then die. I can either put more gas in, which helps cool the gas, or wait for a while until it cools down. I will list what I have done to try to fix it, and my thoughts on what is still causing it.

    Fix actions taken so far.

    1) Replaced the sumpped fuel tank and twin external Walbro in-line pumps with a Cobra tank and an in-tank Aeromotive A1000.
    2) Heat shielding on all fuel lines under the hood, or near the exhaust. (Damn my exhaust is hot! Without touching the rear bumper cover, my exhaust tips have melted the bumper cover.)
    3) Removed the Fuel Rails and Fuel Pressure Regulator and wrapped them with thermal reflective tape. (I can drive for 30 minutes, then pop the hood and touch the rails now, before they would burn me an hour after driving.)

    My thought for fixing the problem.

    1) I have PTFE Stainless Braided fuel lines. The PTFE is thin, and sitting right on the braiding. That could be heating up the fuel, but I think this is maybe about 1/10th of the problem. I am thinking about going back to some Russell Push-Lok lines. At least that way, the rubber is some sort of insulation from the heat.
    2) Fuel line size. With my current setup, I have a -10 coming out of the pump to a Y-block just outside the fuel tank. This splits into 2 -6 lines that feed each side of the fuel rails. (this is partly left over from the twin external Walbros.) Then 2 -6's into each side of the FPR, and a -6 return line.
    I am thinking about upping the fuel line size, and running a single -8 to a y-block right behind the fuel rails. It would still be -6's into and out of the rails and into the FPR. I would make the return line a -8 as well.
    3) Header coating/wrap. I really don't want to remove the headers to get them coated! I have Pypes SS headers, so if they get some staining on them, I don't think that would be so bad. They are already purple and gold from the heat. If I wrap them, I would use the DEI lava crap (aka Titanium).

    I would like some other input.

  2. crap, I think I hit back while I was typing this and put it in the "talk" section not the tech.......

    Mods, feel free to move it!
  3. never let tank get below a quarter tank this keeps pump cool and increases its longevity

    anyways sounds like you have a weak pump and or clogged fuel filter, replace filter if not fixed install a NEW pump not a used one
  4. I typically don't go much below half tank, but yes, I understand that concept.

    I just put in a BRAND NEW Aeromotive A1000 fuel pump, the filter was NEW as well. I think when I said "replaced", it might have been confused with "used". Just wanted to clear that up.

    I think I have too much flow with the size lines I have, but I want to get some other opinions.
  5. Fwiw I have personally seen more than one aero motive a1000 do exactly as you say. On a mustang I previously owned the pump would overheat after about an hour of driving and lose pressure. The solution for mine was an aero motive pump controller, after that was installed I never had another issue. As far as the sizing goes, -10 to the pump -8 to the rails and -6 return should work (that is how I had mine setup and after the controller no issues)