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Best way to drain 3yr old gas?

Discussion in 'Engine/Tuning' started by hmwave, Mar 22, 2020.

  1. hmwave

    hmwave . Established Member

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    2003 Terminator has sat inside protected garage for last three years with a 1/4 tank of fuel which was fresh then and well treated with Stabil. It was run for 15mins to run it through.
    The Mobil 1 synthetic was changed back then, and battery has been on float charge since that time.

    What’s the best way to flush out the old gas before it’s started again?
    Is there some way to connect drain hose to fuel rail and use fuel pump to push it out before filling with fresh gas?

    Thanks.
     
    Last edited: Mar 27, 2020
  2. 01yellercobra

    01yellercobra AKA slo984now Established Member

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    I'd just fill the 3/4 with fresh gas and let that run through. Maybe with some Seafoam to help. Then change the fuel filter shortly after you run a bit of the new gas through. Did that with my mom's old T-bird that had sat forever.
     
  3. hotcobra03

    hotcobra03 Well-Known Member Established Member

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    I pulled gas from my cobra when it was down

    I ran power to fuel pump at connection in rear bumper

    Than attached hose fuel line just before the rail.

    There is an old school pull type connection just below passenger head

    Took mins to drain
     
  4. hmwave

    hmwave . Established Member

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    Thanks.

    Thing is I’ve had opinions both ends of the spectrum, some saying I must drain not to damage parts (including an SVT dealer), some say fill it fresh and stay off boost until that tank has burned through.

    Just not sure.
     
  5. hmwave

    hmwave . Established Member

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    Question on running power to pump.

    Why the need if I can use vehicle power?
    Why wouldn’t the accessory key position work?
     
  6. hmwave

    hmwave . Established Member

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    Just checked and I see the disconnect.
    Just pop off the metal clip and pull apart?

    I have fuel disconnect tools, just been so long since I've used them, just want to be sure if they are needed for that connector.
     
  7. olympic

    olympic Well-Known Member Established Member

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    The pump only runs for a couple seconds to prime the system when you turn the key on. The pump wont stay on unless the engine is running. If you can borrow a professional level scan tool you can turn the fuel pump on with that. If not, then powering the pumps directly at the rear of the car is the next best option.

    Hopefully the injectors aren't gummed up. Might have to have them cleaned if it wont start or runs rough.
     
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  8. lOOKnGO

    lOOKnGO Keep'um smiling Established Member

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    You should pull the injectors,.
     
  9. Coosawjack

    Coosawjack Well-Known Member Established Member

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    Fill it up with 93 octane and drive it!!:cool:
     
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  10. Chancey

    Chancey Auto Affection Established Member

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    +1 on this... after filling with 93, add a good can of techron fuel system cleaner and keep the go pedal stomped!
     
  11. NateDogg

    NateDogg Terminator Established Member

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    Yup I agree. Only 1/4 in there? Fill it up the rest of the way and run through the tank.



    Sent from my SM-G970U using Tapatalk
     
  12. 01yellercobra

    01yellercobra AKA slo984now Established Member

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    I wouldn't stomp on it until this tank is run through though.
     
  13. COOL COBRA

    COOL COBRA Hell Yes! Established Member

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    Add some Seafoam, run 4th gear down the hiway, stay out of boost, run it down scary low, re-fill w/ fresh gas,
    HAMMER on it! That's the quick-easy-efficient way.
     
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  14. hmwave

    hmwave . Established Member

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    Thanks for all the help, much appreciated.

    I decided to drain and refill fresh before starting.
    Been a while since I tinkered with it so had fun doing so...

    Steps:
    1. Key off, disconnect fuel line at passenger side fuel rail. Pull metal retaining clip, use fuel line disconnect tool to release connector. Heavy rag underneath to catch slight fuel spillage. Leave clean rag loosely inserted into fuel rail end for now.
    2. Use 5ft 3/8” internal diameter fuel hose pushed over fuel line fitting, tape with electrical tape to ensure it doesn’t come loose (yes, overkill but safety first as fuel is being pumped). Snake fuel hose into gas catch can. Wrap a zip tie firmly around the hose and push that inside can so hose doesn’t jump out.
    3. Driver side of trunk behind trunk liner, pull connector C433 from FPDM. Jumper pins 2 and 3 together to ground pump (with connector pins facing you, flat side down, pins 2 and 3 are bottom right, 2 is second one in, 3 is next pin toward connector center).
    4. Run two conductors from C433 connector to passenger front, tape them safely high on hood prop WELL AWAY from catch can. Insert one into C433 pin 9, other into pin 10 (the two isolated pins at connector top row at the left).
    5. Key on in run position, don’t crank motor. Use a glove to push together the conductors taped to the hood prop which IMMEDIATELY runs the pump at significant volume. Mine filled a 5gal can in 1-2mins. Drain until tank near empty. Be careful not to create sparks when connecting and disconnecting the conductors given there's gas vapor around. I used a nitrile glove to smother the conductors before touching them together and when separating.
    6. Key off. Fill tank with fresh fuel, I used 10gals with some Seafoam mixed in.
    7. Repeat step 5 running pump for a min or two to get the fresh gas through the fuel lines. Probably takes less time to fully flush but I wanted to be sure.
    8. Key off, disconnect drain hose, move gas can to safe place, and refit fuel line to rail, secure with metal clip in proper position. Rub some clean engine oil on the o-rings before pushing home.
    9. Probably not strictly needed but I also used a rag on the passenger side Schrader valve to flush that rail. Same technique, key on, safely connect the conductors to run pump. BE VERY CAREFUL HERE as this quickly creates fuel vapor and the fuel soaked rag so NO SPARKS. Move the rag to a safe place outside.
    10. Again, maybe overkill, but I pulled the fuel rail pressure sensor on the driver side and repeated step 9 to flush that side. Just takes 5mins. However this time I used the fuel hose to drain into the catch can using a 3/8” inline plastic connector in the fuel hose and held firmly into the fuel rail port as the pump pressure will launch gas out of there. Be very careful. 'Measure twice, drain once'.
    11. Key off, move gas can to safe place, refit pressure sensor, a little clean engine oil on o-rings.
    12. Pull the jumper and conductors from C433, reconnect it to the FPDM.
    12. Clean up, recheck all connections. Key on, fire her up and head out to burn through that Seafoam!!

    You'll probably need to clear codes as the ECU typically posts an FPDM related code given you'd disconnected it.

    I also plan to fit a new fuel filter.

    Over subsequent fills, pour a gallon of the stale gas into near full tank each time, or dump it in your clunker, burn it up.

    And, don’t let the car sit for three years again unused!
     
    Last edited: Mar 27, 2020
    03cobra#2 and Fastback like this.
  15. c6zhombre

    c6zhombre E85 NutSwinger Established Member

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    04sleeper has a tune on the sct handheld "drain tank". You hook a hose up off the fuel rail valve to a fuel jug, load the tune....the pumps run 100%. He says it will drain the tank damn fast.

    Never had to use it.....but very nice to have!
     
  16. Coosawjack

    Coosawjack Well-Known Member Established Member

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    Why did you even bother asking then??:cool:
     
  17. hmwave

    hmwave . Established Member

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    ? ? ? ? ?

    To solicit helpful answers.
     

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