1. Join the Community!

    DSMtuners is a massive archive of DSM information - but more importantly, it's a COMMUNITY! Join in and participate with other DSMers, and invite all of your DSM friends to make this place their home. Chat with others, create a build thread, post questions and answers. Get involved! Logging in will also remove many of the advertisements, along with this notice. ;)

Whats the REAL Difference between a 90-91 ECU?

Posted by MR2fanatic, Feb 10, 2004

Please Support Rix Racing
Please Support STM Tuned
  1. MR2fanatic

    MR2fanatic Probationary Member

    6
    0
    Joined Feb 3, 2004
    Hackettstown, New Jersey
    Guys,

    FOR A TSI AWD 5 SPEED

    Whats the difference between the 90 ECU and 91-94 ECU's? Are there some wires that are in different positions? Are the 91+ EPROM? Do the 91+ ECU's physically fit in 90 cars? Thanks for the help.
     
  2. psychlow

    psychlow Proven Member

    2,866
    13
    Joined Jun 30, 2003
    Colorado Springs, Colorado
    - All 90's are EPROM.
    - 91's may or may not be EPROM

    There are two wires swapped between the two ECUs.

    Also, ECU has a wider range of fuel control on 91+ than on the 90's.
     
  3. Morphius

    Morphius DSM Wiseman

    1,889
    45
    Joined Jun 9, 2003
    M-Town, Michigan
    You've got it backwards.
    All 90's may or may not be EPROM.
    - 91's are EPROM


    True.


    I'm not sure where you got that. Basis for claim?
     
  4. LightningGSX

    LightningGSX Proven Member

    628
    4
    Joined Jan 15, 2003
    St Paul, Minnesota
    91's do have a larger fuel trim swing and the Idle switch and MAF reset pins are swapped.90 and 91 both may or may not have Eproms.
     
  5. psychlow

    psychlow Proven Member

    2,866
    13
    Joined Jun 30, 2003
    Colorado Springs, Colorado
    I agree now that all 1G model years may or may not be EPROM after more research. All of the 90's I've seen were EPROM and I saw that written somewhere, but I was misinformed, sorry.

    Fuel trims on 90's auto-adjust from 100 +- 20% if I remember right.
    Fuel trims on 91's auto-adjust from 100 +- 40% if I remember right.

    Don't quote me on the exact numbers! I'll see if I can find documentation to back this up.
     
  6. psychlow

    psychlow Proven Member

    2,866
    13
    Joined Jun 30, 2003
    Colorado Springs, Colorado
  7. kpt4321

    kpt4321 Proven Member

    3,393
    13
    Joined Jul 30, 2002
    90 ECU's have two pins swapped, change these in the harness and you can run the other ECU.

    They are the exact same size.

    90 fuel trims have a range of 40%, and 91+ has a range of 80%.

    90's have less agressive timing maps, and slightly richer fuel maps.
     
  8. Laser-man

    Laser-man Proven Member

    506
    1
    Joined Sep 10, 2002
    ,
    all 90's are e-prom
     
  9. boostedinaz

    boostedinaz DSM Wiseman

    3,839
    16
    Joined Dec 22, 2002
    Scottsdale, Arizona
    Wrong, I have a 90 Laser and it didnt have an EPROM in it. When it took a shit I went to a junk yard and pulled 4 ECU in all the 90 cars they had and none of them were ERPOM's. The 90 ERPOM's are the hardest to find and very expensive. The one I found after three months cost me 300 bucks and didnt even come with an aftermarket chip.

    Michael
    :laser: :talon:
     

    535  0

    1991 Mitsubishi Galant VR-4
    manual · Galant VR-4
    Loading...
  10. LightningGSX

    LightningGSX Proven Member

    628
    4
    Joined Jan 15, 2003
    St Paul, Minnesota
    I own a 90 tsi and a 90 eclipse turbo FWD, neither have Eprom ECU's.
     
  11. MnDSMer

    MnDSMer Proven Member

    11
    0
    Joined Mar 25, 2002
    ,
    If you are doing a swap from a 90 to a 91-94 there is more then just swapping the wires on the ECU. You also need to swap the coil pack and ignition transistor from a 91-94 in. Also you don't need the noise filter any more, so you can just cut the plug off and connect the wires together. Here's a link to a more detailed description of the swap.

    http://www.ecanfix.com/~mdhamilton/ecuconversion.html
     
  12. DevilSperm

    DevilSperm Proven Member

    3,665
    18
    Joined Oct 28, 2002
    Holdrege, Nebraska
    TPS and CAS are also different ...if your doing the swap
     

    607  0

    1991 Eagle Talon TSi AWD
    11.296 @ 120.790 · 1G DSM
    Loading...
  13. 1990EclipseGSX

    1990EclipseGSX Proven Member

    317
    16
    Joined Apr 7, 2003
    Angel Fire, New Mexico
    Again, all 90's DO NOT HAVE E-PROMS! I have a 90 and man was an E-PROM ECU a real PITA to find. Also ran me a pretty penny.
     

    383  0

    1990 Mitsubishi Eclipse GSX
    12.277 @ 117.715 · 1G DSM
    Loading...

Share This Page

Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Feal Suspension Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com OHM Racing Raven Fabrication RixRacing RockAuto RTM Racing SouthBay Fuel Injectors STM Tuned VR Speed Factory