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No VTEC

Discussion in 'ECU's, Electronics, and Tuning' started by PsychoREX, Apr 4, 2012.

  1. PsychoREX

    PsychoREX New Member

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    OK so am running a 95 civic ex body harness & engine harness with a chipped p28 on a 96 JDM ITR engine & my VTEC won't seem to engage.

    I check the oil level & its good.

    I check the connections at the ECU & they are good.

    All sensors are connected in there designed places according to the color going from the computer to the sensors them themselves.

    What else should i check???




    And BTW the JDM ITR does not have a oil pressure sensor by the VTEC Solenoid. Both wires from the ECU are together going to the VTEC solenoid. I had it like that before I took out my harness and it worked perfect, not sure whats missing now.


    And well if I can't get it to work automatically, how do I hook it up manually?
     
  2. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    first do you have any check lights on.
     
  3. PsychoREX

    PsychoREX New Member

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    I dont have a stock cluster this is a fully gutted CRX race car with an integra da dash board & some autometer gauges so i don't know if i have any codes, am running a spoon chip with spec like this

    VTEC Enable: 4500 RPM
    REV Limit: 9400 rpm
    Idle: 850 rpm
    Knock Sensor: DISABLED
    O2 Sensor: DISABLED
    Injector Test: DISABLED
    Speed Limiter: DISABLED
     
  4. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    its gonna be a bitch to find it without a check engine light, may have to dig up where the light would be on the ecu and rig one up and see, but my first guess would be the computer is looking for a pressure switch.
     
  5. PsychoREX

    PsychoREX New Member

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    What light are u talking about?


    And how do just wire vtec up to a switch? Do i just need to run 12v power to it?
     
  6. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    yes, but even on a switch it wont work like a true vtec bc the ecu changes the fuel curve and other things as well.and somewhere on the pinout for the ecu, will be a way to check for a check engine light, but ive never had one hacked up that bad so im not sure how to do that.
     
  7. PsychoREX

    PsychoREX New Member

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    Hmmm am not sure what your trying to explain, but well ive checked the solenoid & it does click. My coolant temp sensor is connected cause i matched the color from ECU to the plug, umm what else? I have no pressure sensor cause its a JDM ITR engine so both pins from the ECU are hooked together going to the solenoid.


    Basically i have taken out oil level, coolant temp, the solenoid, the ECU, the VTEC connection at the solenoid, speed sensor & rpm signal out of the possible problems so I pretty much have ran out of possibilities.
     
  8. PsychoREX

    PsychoREX New Member

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    So your saying that the ecu changes the map on a obd1 ecu when vtec is engaged

    That i have never heard of, so why do people even bother doing the vtec switch for?
     
  9. CAFROG

    CAFROG Honda Minion VIP

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    If you have a USDM ECU (chipped).....won't it look for a pressure switch??
     
  10. CAFROG

    CAFROG Honda Minion VIP

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    I say you find a b18c1 VTEC set up and try it. Or a JDM ECU like a p30 or p72 OBD1
     
  11. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    because there idiots and just want the pop/sound of vtec,without getting anything real from it.
     
  12. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    that^^
     
  13. PsychoREX

    PsychoREX New Member

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    I have 2 chipped obd-1 p28 computers & 3 different chips that i have tried, but none of them seem to make VTEC engage.

    Also VTEC was working perfect before i took the whole body & engine harness out, but i never messed with any of the wires, so i might just be missing something stupid.

    Today I was looking at the wiring diagram & made sure that the right color wires were going to the coolant sensor. Should there be voltage going to that sensor?

    Also have another question is there any grounds in the computer that would make VTEC engage?

    My next test is going to be that i am going to hook up a DVOM to the VTEC wire that i have running to the solenoid & see if is getting voltage at the specific rpm that VTEC should engage.
     
  14. PsychoREX

    PsychoREX New Member

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    What do you mean by bypassing the VPS? How do i proceed with that? And how would VTEC engage automatically if there is no VPS signal?
     
  15. PsychoREX

    PsychoREX New Member

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    Also there is this sensor on side of the ITR head that i am going to take a picture of & post it, but it is located a little bit under the VTEC solenoid. What is that sensor?
     
  16. PsychoREX

    PsychoREX New Member

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    I already did this / i have a4 & d6 tapped together & then ran a wire going to the VTEC solenoid / i have had it like that forever. There has to be some other problem.


    I am probably going to have to see if i can find a 92-95 civic cluster & get the harness to see if i can pull the codes.
     
  17. CAFROG

    CAFROG Honda Minion VIP

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    Yeah....it sounds like something happened when you last had stuff apart.
     
  18. PsychoREX

    PsychoREX New Member

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    Never mind i switched around the sensors from the coolant & some other sensor thats below the VTEC solenoid & VTEC is BLASTING!!!!!!!!!!!!!!!!!!!!
     
  19. CAFROG

    CAFROG Honda Minion VIP

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    Never mind? Sounds like I hit the nail on the head! lol

    So bitter sweet when it's something stupid
     
  20. PsychoREX

    PsychoREX New Member

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    Well yea it was something stupid but considering that i don't have a cluster wiring harness or cluster itself installed to read check engine lights, it was pretty much a guessing game between swapping engine plugs lol
     
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