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Discussion Starter · #1 ·
Easyest way to undo the wiring harness is? (not from the engine so were do i get at it under the dash by the ECU but is it just conected? thanx for your help guys.

And what else needs to be taken off to get engine out exaust now would it be easyer to unhook tranny or drive shaft?

And on the other side what needs to come off to take it out? I have the left side done exept for exaust right now.

Digital Dreamer
898 Posts
The wiring harness is connected to the ecu which most people will say can easily be accessed by taking out the glovebox. The 2 screws I believe and the ecu is out and you can disconnect the wiring harness and push it through ther firewall and pull it with the engine.

1/2 Na-T Project
987 Posts
Follow this list...Taken from, Dr Jonez Site

This procedure is for STOCK 5-speed MKIII Supra Turbos. There may be specifics that are different for automatic transmission and/or NA Supras and/or different levels of modification.

Put the car up on 4 jack stands - use the standard jack points for the stands. Be SURE the car is steady and secure before climbing under it.

Cover the front quarter panels and front fascia. Protect your car from scratches and dings!

1. Roll ALL windows up. You will be removing your battery and the windows won't go up once the battery is out. (I’d call this step optional depending on where you’re doing the work, I always leave my windows down, then again, I’m in a climate controlled shop…)
2. Attach a 19mm 6-point socket with a breaker bar onto crank pulley bolt- click engine over to bust the bolt loose (works like a charm).
3. You have two options on the hood: A. Disconnect the hood struts where they attach to the hood. You can use a cord tied between the hood latch and the spoiler (or something else behind the car) to secure the hood in a near vertical orientation. B. Scribe the hood location on the brackets (this will aid reinstalling the hood later) and remove the hood (12mm bolts).
4. Remove the bottom engine undercover if you still have one.
5. Drain the transmission fluid, engine oil, and coolant. Do this as you perform other tasks. You might think it not necessary to drain your expensive synthetic transmission oil, but if you don't, it will come out the rear of the transmission while you are pulling the engine out with the hoist, so do it now.
6. Open gas door and remove gas filler cap - leave door open (to remind yourself to put the cap back on).
7. Remove battery
8. Remove glove box and trim- philips screws.
9. Disconnect all engine wiring harness connections- ECU, HAC (if you have one), body, ABS, etc.
10. Pull main harness grommet the off firewall from the outside w/small standard screwdriver. Pull the main harness and connectors through the grommet hole and lay it on top of the engine.
11. Remove the black radio/climate control surround piece.
12. Put transmission in neutral.
13. Remove shifter boots (all 3 of ‘em!, 10mm bolts).
14. Remove shifter, but leave in car (10 mm bolts).
15. Stuff a rag in the gearshift hole of the transmission. This is to prevent dirt, undercoating, foreign objects, etc. from getting in your transmission.
16. Remove turbo heat shield (14mm nuts).
17. Remove the exhaust. Depending on your exhaust, it may be easy to just remove the downpipe (can take elbow off if you must). If the nuts and bolts between the downpipe and the second cat are impossibly frozen, you can remove the entire exhaust as a unit. Remove the three downpipe to turbo elbow nuts first. Use a 14mm 6-point socket and a universal joint with a long extension. Another option is just disconnecting the downpipe from the cat and leaving it attached to the engine. It may or may not be in the way when you pull the engine/trans, it depends on the car/downpipe.
18. Remove driveshaft. Separate the driveshaft from the differential first (14mm nuts/bolts). You can use the parking brake to keep the driveshaft from rotating as you loosen the fasteners. Remove the trans tunnel brace and drop the carrier bearing assembly. The driveshaft pulls straight out from the rear of the transmission. It’s a good idea to plug the end of the trans so it doesn’t leak too much oil. A WD-40 cap with about 4 layers of duct tape works great.
19. Remove speedo cable from transmission. Stuff a clean rag in this opening also.
20. Remove clutch slave cylinder and mount that holds the hydraulic line to the transmission. Place the slave cylinder out of the way, but be careful not to kink or stress the lines or hoses.
21. Remove fuel lines. Remove fuel feed line at the union just to left side of slave cylinder (take the little black plastic cover off. - use 2 FLARE wrenches (if it won’t break free- spray WD40 or equiv. on it and do this later – BUT DON'T FORGET). Remove the rubber fuel return line, its right next to the fuel feed. Gasoline will drip out and down your arms - be prepared. If your tank is full, there is the potential to drip a lot of gasoline here. Be prepared to plug the supply and return lines leading to the rear of the car. A section of rubber hose capped at one end with the right sized screw or bolt works fine.
22. Remove the ground wire/strap between the transmission and body in this area - don't be surprised if it is missing - undo it if you have it.
23. Remove the fender to 3k pipe IC pipe.
24. Remove the accordion hose from the turbo and remove AFM/filter.
25. Remove the turbo compressor outlet to intercooler IC pipe.
26. Undo upper and lower radiator hoses - take them off at engine too.
27. Unclip the electric fan wire(s) depending on year.
28. Disconnect the coolant reservoir hose at the top of the radiator.
29. Loosen the 4 12mm bolts that hold the fan to the water pump.
30. Take the fan out with the radiator - hold the fan to radiator and lift all it out. Tighten the radiator drain plug now so you don't have to remember later.
31. Loosen PS pump adj. bolt and alternator adj., and the A/C belt idler and take all the belts off.
32. Unbolt the A/C compressor. There are four long bolts that go through the compressor to the bracket - leave the bracket on the engine. Loosen the 4 long bolts with ratchet for some and you will have to use a 12mm wrench for others. The top two may be hard to get out - it's OK to leave them in the compressor. Make sure the compressor is free from the bracket. This saves you from having to evacuate and refill your A/C system.
33. Remove the PS pump bolt from the PS pump mounting bracket and position the PS pump out of way.
34. Remove ground strap from rear exhaust side of the engine (firewall to the head).
35. Remove the 2 throttle cables (one from the gas pedal, the other from the cruise control actuator) from the throttle bracket and place them out of the way.
36. Disconnect wires around where the fuse box is - you will see what can stay with the engine to come out. Leave as much hooked to engine as humanly possible - makes reassembly much quicker. - the DIAG block comes out with the engine harness and engine.
37. Remove the brake booster line off of manifold and turn upward.
38. Take the vacuum line off of back on intake manifold (by EGR) - It is a very good idea to remove the nipple it attaches to - it is easy to break.
39. Take both heater core hoses off - one on the passenger side by the charcoal canister and the other on the driver side near the brake booster. Position a piece of wood near the one by the brake booster or it may be smashed when you take engine out.
40. Put a jack under the transmission, but forward from the mount to the body. Use the jack to take the weight off the transmission crossmember.
41. Unbolt the transmission crossmember from the body and from the transmission.
42. Remove the 2 17mm engine mount nuts – on ‘90+ and some later ‘89s you may want to unbolt the mounts on both sides (top and bottom) of mount or they may break (or they are already broken).
43. Unbolt the front stiffening bar at the rear of the front suspension subframe, under the oil pan.
44. Remove oil cooler lines by the I/C on the right hand side - be prepared to plug both the oil cooler hard lines and the oil cooler hoses if you don't want oil trails and/or puddles on the floor. A sandwich bag over the end and a rubber band will work OK.
45. Get an assistant - engine removal should never be done solo. Have them verifiy that everything is disconnected and that the engine is ready to come out.
46. Jack the hoist all the way to sky and release it to let it bleed all the air out. Be PREPARED for the hoist to drop the engine - just in case.
47. Attach a chain around the lift hooks by alternator and passenger back of engine. Make sure you are working with a good chain and hardware! Don't skimp here. If you aren't sure the chain and fasteners are strong enough, they probably are not. You may want to stuff a bolt through the chain links on either side of the hoist hook to prevent the chain from sliding through the hook at an inconvenient time. If you can get a load leveler, get one - it will be easier. SLOWLY jack this thing up. The engine will barely clear the oil pan over the center support.

Some reinstallation thoughts:

If the car has ABS, LEAVE the harness that runs over the transmission to the passenger side out of the clip on top of the transmission. You will thank yourself on the next BHG won't have to drop the transmission down to disconnect it...simply take the harness out of the other clips and pull it down on the passenger side...just enough room to unhook it.

Putting the engine in presents a few other problems as well! It is 10x easier to pull the engine because the transmission "naturally" follows the transmission tunnel and comes out on it's own angle. . The engine/trans needs to go in at a 40 degree angle or so. Also lube up the motor mounts so they slide easily into place

You may want to use a floor jack to lift transmission up as you put it down in, this helps to get it right in.
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