SR20DE - pretty horrendous on fuel?

Thread in 'Technical Questions' started by Bu11et, Jul 19, 2017.

  1. Bu11et

    Bu11et Well-Known Member

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    In my S13 - I fitted a completely stock S14 SR20DE(VVT) bar the exhaust manifold and exhaust, the rest of the engine is completely stock, but for an NA - it seems pretty horrendous on fuel... Like it'll probably do 40 miles to a tenner if im lucky, and that's driving steady!

    Im running a 6 speed S15 Box and a 3:9 diff - so not horrendously short gearing either!

    I've had a snoop around the engine bay and cant find any obvious fuel leaks, I've yet to check under the car but just wondering if theres anything else I can check once I've ruled out the above...


    Ta,
    Charlie
     
    #1 Bu11et, Jul 19, 2017
    Last edited: Jul 19, 2017
  2. r3k1355

    r3k1355 Well-Known Member

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    Lambda sensor and engine temperature sensor are good places to start.
     
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  3. Bu11et

    Bu11et Well-Known Member

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    How can I test these? Never had much dealings with this sort of stuff before unfortunately...

    Just seen prices and its looking like £20 for a new Temp Sensor which is fine, but as above, how can I test them to make sure the wiring is even working?

    Butchered loom as its an S14 SR20DE into an S13
     
  4. r3k1355

    r3k1355 Well-Known Member

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    oh right, no fucking idea then I'm afraid.

    I know the S13 has a separate mini-manual for some electrical bits on the engine, including testing procedures for them (You used a multi-meter on the sensors I think)
    Not sure if the same is true for the non-turbo SR engine though, you'll have to spend some time going through workshop manuals to see what the diagnostic procedure is on those sensors.

    Problem is the sensors could be totally fine and the issue could be with dodgy wiring, all it takes is one crossed-wire or one bad earth and it all go's to shit.
     
  5. Bu11et

    Bu11et Well-Known Member

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    Ye that's my concern!

    I've ordered a new thermostat and temp sensor anyway, only £30 delivered so get them fitted this weekend and see whats what
     
  6. mc_bob

    mc_bob Active Member

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    On idle, the signal wire from the lambda should jump between 0-1v constantly to indicate the fueling is correct, and also when your driving at a constant speed.
    If it hangs at 1v or 0v constantly, something is wrong with fueling (I think 1v is rich, but each manufacturer is different). It doesnt mean lambda is faulty, although could be.
     
  7. Bu11et

    Bu11et Well-Known Member

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    Ah right okie dokie - will give that a go - cheers matey!
     
  8. Bu11et

    Bu11et Well-Known Member

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    Replaced coolant temp sensor last night

    did a 53.4 Mile journey today, mixed between motorway and town stop/start driving - brimmed the tank before hand, then brimmed it when I got back(same petrol station each time)

    used 6.08L of Petrol which is 1.337gallons

    53.4 Miles divided by 1.337gallons = 39.9mpg

    If my calculations are correct?


    This wasn't driving like miss daisy either
     
  9. Cades

    Cades Member

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    test your old coolant temp sensor with a multimeter and bowl of hot water to rule it out
     
  10. Bu11et

    Bu11et Well-Known Member

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    You genius, didn't even think to do that

    EDIT: Although wouldn't that require it being plugged in?
     
  11. Cades

    Cades Member

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    Nah, the resistance will still change as the temp does. Just put the multimeter on the pins. Can't remember what the resistance values should be, but it's in the FSM somewhere
     
  12. r3k1355

    r3k1355 Well-Known Member

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    That seems pretty decent?
     
  13. Mad_Max

    Mad_Max isthisreallife?

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    Was about to say the same. I'm lucky if i get 200 miles out of a full tank.
     
  14. Bu11et

    Bu11et Well-Known Member

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    Ye mega happy now haha

    Especially with the drive to Driftland tomorrow!
     
  15. p555ben

    p555ben Active Member

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    pft im lucky too get 160miles out a tank with captain slow ha ha ha ha
     
  16. Bu11et

    Bu11et Well-Known Member

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    no way!! Sure that's mapped correctly? that's ridiculous!

    Just did Driftland in Scotland, and its 260ish miles each way, cost me £35 in fuel each way, and then £35 of fuel for drifting all day Thursday
     
  17. p555ben

    p555ben Active Member

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    I'm messing lol I get loads of miles out the trusty captain
     
  18. Bolf

    Bolf Resident Nut Job.

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    even the Autech we had was good , that had injectors , cams and intake from factory too
     
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  19. Bu11et

    Bu11et Well-Known Member

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    I'd love to get an autech engine and fit it in my 13 - would be a right little ripper!
     

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