Changing from Auto ECU to Manual questions ( ran into some problems HELP!)

[Angry7M]

Ok so I did an auto to R154 swap a few months ago on my 89+, but i kept the Auto ECU and harness. Now i want to swap in an 89+ Manual ECU and Harness. So i was wondering if theres anything else i need to do besides changine the ECU and harness? Also is there a difference between the auto ECU and the Manual ECU (besides the connectors) ? Thanks

 

[Nocheez]

There's really no reason to do it. If you've got the wiring done and everything works, why bother?

 

[Angry7M]

There's really no reason to do it. If you've got the wiring done and everything works, why bother?

Ohh i have my reasons................just wanted to know if there is anything else i should do before the wiring and ecu swap .

Thanks

 

[Davismj711]

If the reason is that your going to run an AEM or other stand alone management system you can do as I did.
I changed the Auto ECU for a Manual ECU. No body or engine harness necessary. It is plug and play ^^

 

[noah89t]

as stated before, no reason to change the harness.
but to answer your question, no there isn't anything you need to do. just make sure you stick with the same era of harness (87-88 or 89+)

 

[Angry7M]

as stated before, no reason to change the harness.
but to answer your question, no there isn't anything you need to do. just make sure you stick with the same era of harness (87-88 or 89+)

OK guys thanks for your help.

 

[iwannadie]

With the auto ecu doesnt the engine idle high when your in N? Im doing my swap soon and plan on getting a manual ecu because of that. I also thought the harness is the same between the 2 ecus not sure why youd swap them?

 

[Nocheez]

With the auto ecu doesnt the engine idle high when your in N? Im doing my swap soon and plan on getting a manual ecu because of that. I also thought the harness is the same between the 2 ecus not sure why youd swap them?

The automatic ECU doesn't do anything differently as far as I can tell. My car revs up a bit on start up to get the motor warm, but once it reaches operating temperature it drops back down to 650 RPMs or so.

 

[Angry7M]

Ok so i started to swap the Manual 89+ harness into my 1989+ supra. But i noticed that there are 4 other clips that hook up somewhere to some wiring that comes out of the upper dash. The problem is that out of those 4 clips the white clip is bigger on the manual harness and on the other 3 clips the pins don't match up with the wiring that comes from the dash. (pretty hard to explain and i don't have a camera)

What do these four wiring clips go to??? And also I thought it was just plug N play like i was told on here???



Both wiring harness have the gray ECU plugs.

My original ideas was to swap out the auto ECU and harness for a Manual Harness and ECU. Im doing this because i couldn't find an auto harness that was in good conditions to replace my current one, since the one currently on the car is all messed up. So i found a manual harness and manual ECU in very good conditions for a good price and i decided to swap them, but now i ran into this problem

 

[Angry7M]

Anyone?????????:nono:

 

[noah89t]

are both harnesses from the same year? 90-92 harnesses may have air bag plugs even thought they are still gray plug. i'm not saying that is the problem, just a question

 

[3p141592654]

There are 24 engine wiring harness variants for 89+. Many are obsolete, but the point would be that this is not as simple as made out on this thread.

82121-14530 1 08/1988 - 08/1989 MA70..5F..TWC
82121-14531 1 08/1989 - 08/1990 MA70..5F..TWC
82121-14540 1 08/1988 - 08/1989 MA70..4FC..TWC
82121-14541 1 08/1989 - 08/1990 MA70..4FC..TWC
82121-14550 1 08/1988 - 08/1989 MA70..5F..TWT
82121-14551 1 08/1989 - 08/1990 MA70..MTM..TWT..USA MA70..SPR..MTM..TWT..CND
82121-14560 1 08/1988 - 08/1989 MA70..ATM..TWT..USA MA70..SPR..ATM..TWT
82121-14561 1 08/1989 - 08/1990 MA70..ATM..TWT..USA A70..SPR..ATM..TWT
82121-14570 1 08/1988 - 08/1989 MA70..5F..TWC..USA CALIFORNIA SPEC
82121-14571 1 08/1989 - 08/1990 MA70..5F..TWC..USA CALIFORNIA SPEC
82121-14580 1 08/1988 - 08/1989 MA70..4FC..TWC..USA CALIFORNIA SPEC
82121-14581 1 08/1989 - 08/1990 MA70..4FC..TWC..USA CALIFORNIA SPEC
82121-14690 1 08/1990 - 08/1991 MA70..LB..MTM..TWC..USA
82121-14691 1 08/1991 - 05/1993 MA70..LB..MTM..TWC..USA
82121-14700 1 08/1990 - 08/1991 MA70..LB..ATM..TWC..USA
82121-14701 1 08/1991 - 05/1993 MA70..LB..ATM..TWC..USA
82121-14710 1 08/1990 - 08/1991 MA70..5F..TWT
82121-14711 1 08/1991 - 05/1993 MA70..5F..TWT
82121-14720 1 08/1990 - 08/1991 MA70..4FC..TWT
82121-14721 1 08/1991 - 05/1993 MA70..4FC..TWT
82121-14730 1 08/1990 - 08/1991 MA70..LB..MTM..TWC..USA CALIFORNIA SPEC
82121-14731 1 08/1991 - 05/1993 MA70..LB..MTM..TWC..USA CALIFORNIA SPEC
82121-14740 1 08/1990 - 08/1991 MA70..LB..ATM..TWC..USA CALIFORNIA SPEC
82121-14741 1 08/1991 - 05/1993 MA70..LB..ATM..TWC..USA CALIFORNIA SPEC

 

[noah89t]

^^^^awesome find.

 

[Angry7M]

Woah well that sucks..................... the harness i have wont work then. Well since only some of my wirng is messed up ive decided to make one good wiring harness out of the two. So hopefully itll work out for me.


Now the question is...... Since i already bought the other Manual ECU. Can I use my current auto harness with the Manual ECU??? Thanks

 

[noah89t]

yes. i am

 

[Angry7M]

yes. i am

LOL your what??? lol

 

[turbulance_cressida]

Sorry for cutting up your thread...but i got a question? can i use the 88 auto ecu on a 88 manual harness.and would that make a change in my car


can someone answer lol

 

[turbulance_cressida]

is it possible to do that swap?

 

[Angry7M]

Is your car manual or auto?