MA70 --> JZA70 Conversion

[urantia]

2drft, yeah like lambolica said, wanted to keep the digidash and other things that the halfcut didn't come with.

Lambo thanx for going to all this trouble, but look don't worry if it's too much of a pain in the ass, or your brother isn't keen on the idea of taking the supra apart to get to the wiring. I'm making some progress with the wiring.

Thanx for that lumpy! i found it!

So i couldn't sleep last night (becuase of this wiring issue) so i got out of bed quite early in the morning and tried to wire it up, and lo and behold i was able to get the basics needed to start the car and it now starts and runs!! things like the Fuel pump, Ignition and a few others and she started first go, so relieved!! i even worked out a few of the dash wires and what pins they are from. (used a multimeter and hooked one end to the sensor on the engine, and the other end on the plug pins of the old engine until it whent *beep* hello i have continuity!! so now i know what some of those ma70 body loom plug wires are for. Unfortuntatly thats as far as i got and the dash does not light up as yet but i'm getting there without diagrams. (that's not entirely true i have the diags for the jz side of thigs)

motor sounds very smooth, not a single tap rattle or knock to be heard only the fuel injectors firing and the exuast which is quiter with the 1jz blowing thru it. (big difference to the 7m)

I haven't taken it for a drive as i really want the check engine light working, and also things like the temp and oil pressure working so i can monitor things.

I thought i had the hydro fan all set up but it's blasting at full speed, i suspect there are a few more wires that need to be spliced into the right plugs to get that working.

Thanx again.
-Chris
So thats where i am at.

[Lambolica]

Good Times.....

Yeah, what you did there in wiring is what we did, though matt found some MA70 diagrams that help him through it.

MA70 Wiring Diagrams

This is the Document theat Matt used for the origonal end of the wiring and the documents from the site in the first post for the JZA end.

Speaking to Matt this morning He has been looking further in to the wiring than "just getting it going" in regards to the A/C and the ABS etc. it appears that there are a few wiring issues that he missed in regards to thise parts that he is trying to solve. in short in the MA70 alot of the A/C stuff is in the body loom where as the JZA has some routed through the engine loom. as well as that he has found some small differences in things like the A/C amplifyer (different number of pins) that he is working through.

Hope that diagram helps.

[urantia]

Thanx for those diagrams a fair bit of info in there.
I managed to work out a few more wires with the multimeter on the old motor, which then lets me know the corrosponding wire/pin it whent to on the ma70 body plug.

I also got some info from my old ECU, i gave the part number to Graham a wiring guru i found from the old toymods forums, and he has told me this particular ECU and it's different plugs/wire colors was used for a Feb86-Aug87 Supra MA70 Auto or a Jan86-Aug87 MZ Soarer Auto.

Having a hard time getting my digi dash to light up, whats the secret with getting the dash to light up? does it just require the inputs ie tacho, oil pressure, water temp to light up those signals? or it needs to be lit up from another wire to even display anything at all?

[urantia]

well i'm stuffed nobody seems to have a clue with this wiring. Sideshow couldn't help me, graham h couldn't help me. They just don't have any diagrams covering these plugs.
Sure tracing the wires out is an option but i'm unable to get so many things workig, nothing on the dash (even tho i have wired up the water temp, oil pressure, tacho)

No power steering (becusae i can't wire the PPS in)
No hydro fan control (becusae i can't wire that in)
No check engien light again can't seem to wire that in!

I really should of got that dash working before i took it for a test drive. Oh man does it kick arse tho. In 4th gear felt liek about 100km, dropping back to third and feeling the wheels spin up was truly impressive for me. But when i got home the motor was severly overheated. :"(

So what the hell can i do?

[urantia]

Ha i'm still so stuffed. Why Toyota! why did you change the plugs and wire colors for my car!! why am i the only supra owner with these plugs! GRR

I swear if i could just figure out what wires needed connecting to get the dash to illuminate like when you turn the accessories on, then i'd be right to work out the rest.

I have the dash ground wire sussed out, but there must be something important i'm missing that gives it power and i can't work it out. With that yellow rectangle plug which i believe carries mostly stuff to the dash, it has 2 wires putting out an active 12+ which i am not sure about as yet.

As you have said numerous times lambolica alot of the wire colors just match up, and your right, but alsp have discovered a few that are different colored wires. like the nuetral start swith on the MA side is the same color as the starter relay on the 1jz etc.

Well looks like i'm on my own with this.

[lumpy]

well i'm stuffed nobody seems to have a clue with this wiring. Sideshow couldn't help me, graham h couldn't help me. They just don't have any diagrams covering these plugs.
Sure tracing the wires out is an option but i'm unable to get so many things workig, nothing on the dash (even tho i have wired up the water temp, oil pressure, tacho)

No power steering (becusae i can't wire the PPS in)
No hydro fan control (becusae i can't wire that in)
No check engien light again can't seem to wire that in!

I really should of got that dash working before i took it for a test drive. Oh man does it kick arse tho. In 4th gear felt liek about 100km, dropping back to third and feeling the wheels spin up was truly impressive for me. But when i got home the motor was severly overheated. :"(

So what the hell can i do?

Have you plugged the hydro fan computer in yet? (it runs off the engine loom) Are you using the jza70 radiator with the temp sensor in the bottom? (should plug into the engine bay side of the engine loom). Also have you put the undertray back on as this improves airflow thru the engine bay - I noticed some differences with and without the tray on.

PPS computer needs a speed signal from the dash.

I am sensing that you're going to need to take the instrument cluster or dash out to trace some wires. Urantia with pen and paper and lots of time features heavily in my crystal ball!

What wires run from the ignition switch to the dash?

Otherwise if you can put them up for a few days I'll send my parents down for a tassie holiday and my dad can do it for you!

[urantia]

yep hydro fan computer is in and attached to the 1jz engine loom plug, yep using jza radiator and thermo thing down the bottom is wired in. Fan just blasts at full speed, i know there is something from the dash end that needs to be spliced in. (speed signal which i'm yet to find)

Dash comes out tonight then! I had a picture of someone powering the whole digi dash from a battery charger but i cannot see which wires he was using, if i have the dash ground one sorted, then that probable means there is just 1 wire to give it power that i am missing. *rubbing hands* excellent this could be it!

I got qouted $650 to send my looms off to be wired up, but that could pay to get lumpy senior down here to wire it up for me and i could learn a thing or 2 aswell. Tell your parents to get there stuffed packed!

[urantia]

Digital dash done, water temp, tacho, check engine light all done! no error codes either.


Oil pressure appears to be hooked up to turbo pressure, no big deal easily sorted.

All thats left is the hydro fan to be wired into spin accordingly instead of full blast, and PPS computer to be wired in and i am finished!!! findings documented incase someone else comes across these alien plugs.

Oh and AC to be wired in one day (didn't wire in any TEMS, ABS or Auto stuff either)

VERY RELIEVED AND HAPPY ATM

[Lambolica]

Sounds Good Dude, your pretty much where we got to before the car went back on the road. Matt is still friggin around with the A/C and TEMS, ABS but he his almost there.


Good Times....

[lumpy]

Sounds Good Dude, your pretty much where we got to before the car went back on the road. Matt is still friggin around with the A/C and TEMS, ABS but he his almost there.

From memory the L1, L2 and L3 lines from the jza70 ECU are for the TEMS.

[Lambolica]

Yeah I'm pretty sure he knows where he is at but he is just a lazy shit and wouls rather but out driving than under the bonnet.... However we did work out on the weekend that he doesn't have the fan computer installed....

[urantia]

Few i don't have ABS, and took my Tems out so that saves abit of effort. AC i haven't even touched but i know i will have to eventually, then again i live in tasmania and i plan to drive the car into the ground if at all possible. How is Matt going with the AC stuff? tricky to get it working?

Gee there are alot of wires left that must be for the old Auto , tems, abs and cruise control.

[Lambolica]

He is having an issue with it, when he matches the wiring up from the JZA diagram and MA70 diagrams the A/C relay clicks on and off continuously, ATM he has go somthing rigged for use only on really hot days but he thinks there are some differences on the looms at the fuse box end and he has reverse power of somthing

[urantia]

I'm still stuck on the PPS, the PPS computer has 2 wires to the solanoid on the rack, a speed signal from the dash which are both done!

Then there is a white/black wire that goes to a relay, and a red/black that gets power from the ignition.

Well for starters i seemed to of lost that relay, but the relay also has 3 other wires going to it and i believe 2 or 3 of those wires are from the AC side of things. So ah yeah i am abit puzzled how to wire it up to operate with that relay if i only have 1 wire (from the PPS ecu) going to the relay. No AC stuff hooked up so not sure if the relay can operate with just 1 wire! (lumpy still got those handrawn diagrams for wiring the PPS?)

I should correct one of my previous posts, about using a brake line to extend the oil pressure sender unit out of the way so it doesn't foul the AC compressor. There is one problem i overlooked, the oil pressure sender is no longer eartherd to the car due to the brake line bieng rubber. But connecting a wire from the sender to the block or somewhere to get an earth should fix that. (wondered why my oil guage whent to max pressure and stayed there.)


Supra is going well except the temprature creeps up off the scale every now and again, i freak and pull over and the engine seems fine, the hydro fan is pulling thru luke warm air from the radiator, i have purged all the air out of my cooling system, so either the guage is lying or perhaps the radiator is blocked. (but i'd expect the overflow bottle to be erupting with hot coolant which it isn't.

Oh and the hydro fan just blasts at full speed even tho the fan computer is in and wired up correctlty according to diagrams. *Scratches head*

[Lambolica]

My brother is experiencing the same problems as you the fan is going (not sure as to speed) but every so often the temp creeps up 2 or 3 bars for a little bit the drops back down. even when driving at 80-90km/h. He is a little concerned.

I'd like to see some other experience with this to try and recitfy the problem. the Coolant is topped right up and air has been released out of the system but still does it.