1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Issues when hitting vtec (no YO!)

Discussion in 'ECU's, Electronics, and Tuning' started by autox19, Jul 14, 2018.

  1. autox19

    autox19 Member

    Messages:
    124
    Likes Received:
    15
    Joined:
    Feb 25, 2010
    Location:
    Lansnig, Michigan
    Without writing a book, here is the skinny. Jdm b16 stock with header. Bought 8 years ago ran sweet. Swapped into a fiat x19 and finally got it done last year. Spun bearing before I could run it into vtec. NOTE: if engine sits for 7 years, prelube like it was a new build. Replaced with other stock bottom end. (Used oem head gasket). Doesnt have the umph it did. Part of the reason is it sounds like it is missing once vtec engages. (Tune has it set at 5300 and I can hear it changing) New ngt plugs, new wires, but new ngt wires will be in tomorrow. Running crome with the tune it came with. Tried yesterday to use a base p30 tune and it was running lean even out of vtec (around 17-18) put original tune back in. I dont have a data logger. I am about to swap to Neptune (for a few reasons, data logging being one. )

    Running out of things to check.

    Odie
     
  2. dilbeckskate

    dilbeckskate infamous

    Messages:
    4,287
    Likes Received:
    424
    Joined:
    Aug 20, 2010
    Location:
    Kennesaw Ga
    Lol run it on a stock ecu no tune, and it doesnt have the oof it used too cause its 160 CHP in 1990
     
  3. autox19

    autox19 Member

    Messages:
    124
    Likes Received:
    15
    Joined:
    Feb 25, 2010
    Location:
    Lansnig, Michigan
    It had the same hp when it was in the honda and had umph. The fiat weighs less than the car it came out of so I would expect it to be at least the same. The bottom end was swapped with another stock bottom end. I looked at the pistons and they are both stock pr3. The tune stayed the same. With the same ECU. I dont have a stock jdm ecu to throw in there plus the dizzy is an odb1 (was on the donor car as well) and a custom rywire odb1 wiring harness (to keep the odb0 injectors and resistor box) which is what the donor wiring was like.
    So if you want, take the umph out of the question and go with what would cause it to run rough in vtec.

    Odie
     
  4. dilbeckskate

    dilbeckskate infamous

    Messages:
    4,287
    Likes Received:
    424
    Joined:
    Aug 20, 2010
    Location:
    Kennesaw Ga
    Is it throwing a CEL ? And have you checked your timing ?
     
  5. TurboMirage

    TurboMirage YEEAAAHHH VIP

    Messages:
    25,188
    Likes Received:
    985
    Joined:
    May 20, 2003
    Location:
    Central, MA
  6. dilbeckskate

    dilbeckskate infamous

    Messages:
    4,287
    Likes Received:
    424
    Joined:
    Aug 20, 2010
    Location:
    Kennesaw Ga
    Low oil pressure throws a cel and vtec wont engage
     
  7. autox19

    autox19 Member

    Messages:
    124
    Likes Received:
    15
    Joined:
    Feb 25, 2010
    Location:
    Lansnig, Michigan
    No cel, oil pressure 75+. (Dont remember exactly but I know it is up there) timing 16 degrees advanced 750 rpm with check circuit grounded. I can hear a difference when I hit the rpm. A little louder but then it is missing. Not a consistent miss like one specific cylinder missing. More like stumbling.

    Odie
     
  8. E_SolSi

    E_SolSi Member of the 20 nut club Moderator VIP

    Messages:
    32,850
    Likes Received:
    6,848
    Joined:
    Sep 28, 2002
    Location:
    CT
    how is your compression?
     
  9. autox19

    autox19 Member

    Messages:
    124
    Likes Received:
    15
    Joined:
    Feb 25, 2010
    Location:
    Lansnig, Michigan
    Good question. I will have to check that. Wont have time today. I do know that it is smooth as silk before vtec. Hopefully it won't be raining tomorrow and I can shoot a video

    Odie
     
  10. dilbeckskate

    dilbeckskate infamous

    Messages:
    4,287
    Likes Received:
    424
    Joined:
    Aug 20, 2010
    Location:
    Kennesaw Ga
    Check compression, check screen on vtec solenoid , reset timing to tdc and check marks , use a known good STOCK MAP ecu
     
  11. autox19

    autox19 Member

    Messages:
    124
    Likes Received:
    15
    Joined:
    Feb 25, 2010
    Location:
    Lansnig, Michigan
    I checked TDC (long screw driver method) and it matches up to the lines on the pulley. will google how to check screen. as far as the stock map ecu, what stock mapping ecu would you recommend? the engine is b16a (odb0 injectors with resistor) but the dizzy and wiring are odb1. It will throw an eld code as I dont have an ELD.

    odie
     
  12. autox19

    autox19 Member

    Messages:
    124
    Likes Received:
    15
    Joined:
    Feb 25, 2010
    Location:
    Lansnig, Michigan
    Compression 173ish with 1-2 psi variance across all 4

    Odie
     
    E_SolSi and TurboMirage like this.
  13. autox19

    autox19 Member

    Messages:
    124
    Likes Received:
    15
    Joined:
    Feb 25, 2010
    Location:
    Lansnig, Michigan
    Think I found the issue! New ECU is going to be ordered. Went out to start it and no go. Looked at the ECU. IC14. Is shot.

    Odie 20181013_151553.jpg
     
  14. TurboMirage

    TurboMirage YEEAAAHHH VIP

    Messages:
    25,188
    Likes Received:
    985
    Joined:
    May 20, 2003
    Location:
    Central, MA
Verification:
Draft saved Draft deleted

Share This Page