Engine Harness cleaning

The 1UZFE EGR Delete Kit is available for sale here.

rwdfreak

New Member
Ok here’s the deal. I’m currently figuring the wiring harness. I’d like to remove as many unneeded wires and connectors as possible. I took the time to identify all the wires coming out of the ECU. The ECU and harness is from a 1991 LS400 USDM factory equipped with TRAC system. I still have the car so if by looking at those pictures you think I’m missing some connectors or units please tell me.

The engine is going in a 1985 Celica using the stock w58 tranny. I don’t want/need A/C, car came without it and since temperature is rarely going over 80°F I can live without it. I think it might be a bit hard to make the cruise control work. Maybe I could figure something with the 22re cruise control system later it's simpler in design (pulls a string connected to the TB linkage). Like most people here the TRAC system is something useless (keep that bitch sideway :lol ).

No Clue:
#1: it’s getting in the no clue #2 connector. It’s a 3 wire connector white, red and yellow. I think it was in the tranny loom (outside the car).
#2: just a junction connector I guess some wire goes to chassis ground and others to miscellaneous accessories (cruise control, dash, after cat O2 sensors and probably other) I need to identify which one goes where
#3: similar to no clue #2. My guess is that about half of those will actually be removed.
Are they (#2 and #3) supposed to be TDCL connector?


HPIM3588-mod.jpg


#4: I don’t know if some of those connectors are useful to make the engine run. Like I wrote I think it’s for the TRAC system and the ABS module (On pass side outside the car).
#5: It has the NSW in it. I think it was in the tranny loom, but can’t find what exactly it does. (A/T indicator SW?)

#6: It’s a 6 pin connector: white, blue, black, red, green and yellow. I could not find what it does. The loom goes to the TRAC and ABS ECU white junction connector


HPIM3586-mod.jpg


HPIM3587-mod.jpg



-Fuel pump relay and Resistor plug: I can’t remember if there’s any other resistor, but from the wiring diagram available on the forum it’s part of the fuel pump circuit. From my own understanding I could put it anywhere in or out of the car, probably not too far from the ECU to keep the installation clean (the loom is now separated anyway). I have a constant speed fuel pump if that matters. I might replace the relay with the Celica factory unit.

-OD direct clutch speed sensor: I think this is the signal I need to give from my w58 manual transmission. I could just cut the loom at an approximate length and later wire the speed sensor already on the car. Right?

-Can’t remember how the cruise control box was connected to all of that and where and how the automatic selector was, if so, connected to the Engine ECU. Where should it be connected in the harness?.

-Based on that here’s a list of what I think can be removed form the harness and keep the engine 100% functional:

-No clue #1 (deleting from junction connector)
-ETC solenoid (deleting from 26 pin connector)
-speed sensor #2 (deleting from 22 pin connector)
-Cut “no clue #6” and “going to no clue #5” will release the TRAC crap and unneeded A/T connector. At the same time you release the TRAC and ABS ECU, loom and No clue #4 connector and since it has no use you can dispose how you want. Correct?

Am I missing something? Any advice?!.

Cheer
 
Common!!! nobody, nowere knows anything about this?:tongue:

Where are the 1UZ superheros when we need them?
If you answer any of those question, I'll give a piece of robot.
 

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Well download the relevant wiring diagram for the model of engine (donor car) then do more homework for what you want to put it in and go from there. I mean my Surf with SC400 engine and ECU I spent 8 weeks tracing wiring and removing redundant wiring. removed 50 wires in total, added one and joined 2 and no worries. Had my budget allowed I would've packaged the whole lot up, sent it to sideshow and had the whole lot back ready to "plug and play" within a week, Yet despite the fact his price wasn't too bad my wife objected with the reasoning "You're a mechanic!!! do it yourself" which was duly followed with "Why is this taking so long???!!!"

This is one of those instances where paying someone who knows what they are doing to do something to do something that you are struggling with is worth every penny
 
Thanks for the reply.

I know I have some homework to do, but for me the hardes part is to know how many informations the ECU needs to work properly. My father is a retired electiral engineer. If something goes bad I can always get some help.

Then again my problem isn't to wire or to understand the diagram, but to make it fit with an existing unit. I don't know how Toyota made it and what is interelated. I wont start deleting wires now to realise latter that I need to provide a signal. I know I can pass a wire latter, but it won't be as clean. That's why the tread is intitle "cleaning". I can leave it like that and put it back togeter on the engine, but I'd prefer to get something clean instead. I can play on the harness for an other month and a half before I really start to play on the car as it is stored for winter 100 miles away from home.

I aready did a swap (22R to RE) that I consider harder due to the fact that the truck was carburated and had about only half of the basic wires needed to make an EFI work (no fuel pump, no circuit opening relay, no TCCS, no AFM and much more) and due to it's rarity I couldn't find the truck (1990 canadien carbed) wiring diagram. The 1UZ is hell of a lot easyer to wire since it's self contained and I have the diagram (from here) and the car specific electircal wiring book. Every wires needed to make the engine run is going trough one main harness.

I did some research and couldn't find exactly what I was looking for.
I thought I'd get some help although I know that the information is already on this site somewere.
 


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