Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: JDM 2jzgte Running stupid rich

  1. #1

    Default JDM 2jzgte Running stupid rich

    -jdm non vvti 2jzgte from my Mkiv Supra swapped into a 95 SC300
    -custom harness
    -patch harness for MAPECU2
    -OEM Map sensor
    -USDM cams
    -550cc injectors
    -BW s366
    -380lph inline pump w/fuel cell
    -Tomei FPR
    -AEM uego wideband

    I installed the MAPECU2 exactly per the JDM Non vvti Supra wiring diagram. I will include screen shots of anything specific they may help. im using the JDM2JZGTE MB.tbl map. I start up the car and it starts at 12.5afr and then slowly dips down to the low, low 10s and will not react to me pulling any amount of fuel using "Follow me", even bottoming out the graph. fuel pressure is set at around 29 psi, which I know is low but any more and it runs around 8s in the afr. I unplug the MAP sensor and it does not change anything on how the car is running. not sure what im missing or maybe I can wire it in a different way?

  2. #2


    It sounds like the OEM ECU does not like the load signal from the MAPECU. Can you please clarify exactly which OEM you are using? The JDM one or the one from the 95 SC300? The OEM ECU dictats the wiring diagram and base table.
    MAP-ECU Support

  3. #3


    I'm using the OEM 6 SPEED JDM NON VVTI ECU from my 2jzgte.

  4. #4


    Thanks, ok so I assume you used the JDM wiring diagram too.

    It still sounds like the OEM ECU is not seeing the MAPECU2 MAF output (green wire on 16-way) which in your case replaces the OEM map sensor. I am a little confused when you say you unplugged the map sensor? The OEM map sensor should be disconnected as the MAPECU2 replaces it completely.

    I assume you also have a vacuum line connected to the MAPECU2 built in map sensor?

    A screen shot from the MAPCAL dashboard would helpful.

    MAP-ECU Support

  5. #5


    Alright included some photos of the dash board and how the ecu is calibrated. I rechecked the wiring and everything is wired up per the jdm 2jzgte schematic. The oem map sensor is out of the question now. The only issue is when I try to "pg dwn" to pull some fuel the wideband does not reflect. As well as idle is still rough with black smoke.

    Last edited by sc300drifto; 16th-September-2016 at 03:55 PM.

  6. #6


    Let's worry about the black running rich problem before worrying about the wideband as it does not sound like the OEM ECU is taking any notice of the MAPECU MAF signal which replaces the OEM map sensor OR it is not the map sensor signal at all. The dashboard shot confirms you have good rpm and vacuum and the fuel output voltage looks ok for a MAP sensor replacement. Remember this is not necessarily a MAPECU issue as engine swaps can be notoriously difficult to get right.

    Can you please tell me a little about the engine swap, like:
    1. Did it run ok before you installed the MAPECU2?
    2. What are the impedance of your 550cc fuel injectors and are the same impedance as the ones the OEM ECU you were using expects?
    MAP-ECU Support

  7. #7


    The motor was running great in Japan. And ever since the swap it has been running very rich. The only thing I did to the motor was a full rebuild, same injectors, oem sensors, just an aftermarket harness for the swap. I used a SAFC to tune In japan I kind of figured it would run slightly rich because of the usdm injectors that are in the motor, instead of the jdm ones attached with the resistor required for the conversion from high to low.
    Last edited by sc300drifto; 18th-September-2016 at 01:42 AM.

  8. #8


    Anyone have any ideas? Anymore information needed? Really trying to get this car to run this season.

  9. #9


    Sorry about the delay. None of those things a minor, especially a swap and a full rebuild. The aftermarket harness is also major. Any one of those things could cause your problem. For example, if the OEM ECU is not seeing the MAF signal from the MAPECU green wire, you will get this problem. We have also seen a bad pin on the OEM ECU connector pin.
    Have you checked the MAF voltage using a voltmeter on the OEM ECU pin?
    Have you checked the OEM ECU for error codes to help provide direction?
    MAP-ECU Support

  10. #10


    I do not have any kind of MAF sensor. Only map on my motor. That's how it came from the factory. And the signal from the OEM MAP sensor is cut. The only thing I could really check now is the aftermarket harness. Any places in particular that you would know that would cause such a rich condition? Everything that could cause this problem mechanically, has been replaved/upgraded with aftermarket parts. Thank you for the help with this.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts