Ran into a problem with me swap

Discussion in 'Modifications & DIY how-to' started by emstraumajunke, Oct 23, 2006.

  1. The engine is in but for some reason at an idle with its only idling at 500 rpm is backfires just pops and pops and its running hella rich. only CEL im geting are the O2 sensors which ive always had. Once you get the rpms up it seem to calm donw and no longer backfires but when you let off the gas it pops and then well dies. Any idea. I dont have any kinda of maps to use for break in so i started off running stock, then i loaded my protuned map kinda smooth it out but nt to great still rich, so i loaded the Eco. map and well didnt help any either. so Im kinda suck and confused. Any ideas
     
  2. RamblinWRX

    RamblinWRX Member

    dirty O2 sensor or MAF sensor perhaps?
     
  3. nsvwrx

    nsvwrx Active Member

    dont u need\adiff map for the 2.5 l?
     
  4. Kokopelli

    Kokopelli Active Member

    What code for the o2 sensor? Is it the front or the back?

    the back doesn't matter but unless its completely disconnected it shouldn't throw a code for at least a few driving cycles. I wouldn't expect to see one right away.

    Do you have a way of doing any logging?

    I also second making sure the maf is clean and working right. Find someone close by who will let you borrow their's.

    Check the coil packs as well. The white connectors go to the front packs.
     
    Last edited: Oct 23, 2006
  5. WRX-WRC

    WRX-WRC Active Member

    yeah, with that new block you are gonna need a retune etc for it to run right.
     
  6. crashtke

    crashtke Member Supporting Member

    That sounds like the timing is off...maybe a spark plug wire to the wrong cylinder or the timing belt off a notch? That really sounds like the exact symptoms my Suburban had when the jack hole at the Meiniche shop replaced a couple wires to the wrong cylinders after changing the plugs...

    Also, what injectors are you using currently?

    Edit there was a guy that did this swap that I read about that had same symptoms you described and it had something to do with his timing belt being off a bit...I'll see if I can find the thread.
     
    Last edited: Oct 23, 2006
  7. crashtke

    crashtke Member Supporting Member

  8. nsvwrx

    nsvwrx Active Member

    i dont really know, im justthinking its the TUNE. cant use the 2.0 tune for the 2.5
     
  9. monk

    monk <b>The Kitchen Ninja!!!!</b>

    +1 for the tune.
     
  10. crashtke

    crashtke Member Supporting Member

    But with the backfiring and all it sounds like a timing issue...backfiring = too much fuel in the chamber OR timing firing too late or cylinders firing at the wrong time. I really think the factory computer could figure this out. BUT, if your front O2 sensor got damaged it is going to have a hard time making any adjustments...Just my 2 c
     
    Last edited: Oct 23, 2006
  11. Kokopelli

    Kokopelli Active Member

    The tune will not cause his issues. The fuel trims might be a little off but the idle should be fine. I drove my car for a month during the break in period on the same map I had when I was a 2 liter. Its definatley not a good idea to run it hard without a tune but it should drive/idle fine.

    timing belt sounds like a good place to start.
     
  12. nsvwrx

    nsvwrx Active Member

    ah intresting, i thought they would be completly diff maps...

    yep timing belt sounds like the cluprit then
     
  13. crashtke

    crashtke Member Supporting Member

    is it still dying? Idle at 500 could just be the tach being off...mine shows 500 but when I look with street tuner it shows around 750.
     
  14. nsvwrx

    nsvwrx Active Member

    mine actully idles low around 550
     
  15. the idel dont bother me as much as the whisle sound and the backfires..it almost sounds like an antilag system but not a tuned one
     
  16. crashtke

    crashtke Member Supporting Member

    Well..you don't have exhaust hooked up yet either...you will hear that turbo a LOT more. When I was fitting my race pipe I started her up with just the dp to see what it sounded like, lol. The only part I would be real worried about is it cutting out and backfiring a lot. That sounds like a timing issue to me. I am by no means a subaru expert, but based on having had the same problem on other cars, that is what I would check. Especially considering the backfiring, cutting out and weird idle.

    Edit: is there any way to fit a timing light to these cars? I mean do they have a mark on the crank to check the timing?
     
    Last edited: Oct 23, 2006
  17. hmmm good question. I thought having a subaru Mech. put this thing together would mean less worries but oh well. Cause hes kees tring to say its because my ECU isnt for the Sti. Which my responce my cars not an sti just because the block is out of one dont mean i need the ECU out of one.
     
    Last edited: Oct 23, 2006
  18. crashtke

    crashtke Member Supporting Member

    I would look at the timing...I have read numerous threads about people running their cars with the 2.0 ecu for a while so they could break it in before taking it to get tuned...in all reality I would do the same thing. Tuning does involve some stress to the engine and I would much rather have it broken in before doing that. Exactly what liquid said above. See if there is a way to check the timing. That or the factory o2 sensor (which it uses in closed loop mode) are my 2 bets. Keep us posted! Off to work for me.
     
  19. jonnyboy0150

    jonnyboy0150 Member

    ECU is not the problem. I drove mine for weeks.
     
  20. It was the coil pack somehow he got one side backwards. But we cant seem to figure out what the noise is on the intake side of the motor. It sould like a whislte at idel sometimes but once you give it gas it stops. Its got me confused
     
  21. crashtke

    crashtke Member Supporting Member

    Great! Glad to hear it was something simple! As for the whistling, I would check all the vacuum hoses and hoses attached to the intake.
     
  22. yea the whistling and last night i went fo r a drive to put some easy no traffic few miles on it Cause i was told to stay out of boost for at least 50 to 100 miles. Well when i was on my way home it go a bad hessattion it reminded me of a flat spot on my firends cars like it would loose all power and then try to go. I dont know if this happens at first
     
  23. crashtke

    crashtke Member Supporting Member

    Boost leak? I remember when I first put on my top mount and my dumb ass forgot to tighten the clamp going from the turbo output to the intercooler and it acted kina like that. It also an stupid rich.
     
  24. i would agree but i havent hit any kinda of boost yet
     
  25. crashtke

    crashtke Member Supporting Member

    Well even when you are not hitting boost, you are still running some...think about it, watch your gauge. When you step on it, your gauge goes to 0...that means you are boosting enough to overcome the vacuum that it normally runs. Like I said that would explain the running rich, the backfires AND the whistling.
     
  26. My guages has stayed a - its never been to zero. ANd it used to whistle on idel no its only doing it while driving and not idel
     
  27. crashtke

    crashtke Member Supporting Member

    If you have someone rev it and hold it at rev while you listen can you hear it? Proly easier if you hook the exhaust up, lol.
     
  28. Its hooked up now. It used to start once the car warmed up and when you were driving it would stop now its backwards when you idel it stops and when you drive it gets louder
     

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