1jz to 88 ma70 car wont start

[limitedgt4]

Hi guys.

a little background.

originally i had the car and engine setup with a 2jz harness / 2jz ecu i got from a member car ran fine without issues. i sent the engine to get rebuilt with a 2jz bottom end. the mechanic who did the rebuild suggested i send my harness to dr tweak because some of the connectors were braking off the wires. we got the harness back but it was all messed up so i asked the mechanic to send it back (note: with the messed up harness from tweak, the car started but it wouldnt rev. the TPS signal was in the wrong pin, the Map sensor signal and ground were in the wrong pin, and so many other misplaced wires, but the car started). the mechanic took the harness back and that was over a month ago and we are still waiting to get it back.

meanwhile, i decided to move on and use my jza70 harness that came with the engine and then i bought a jza70 ecu and Map sensor (because tweaks harness damaged mine) from a member in the forums (he claims its good). the jza70 ecu seems to be an oem Denso replacement ecu from what i found on the net. i did inspect it and found no leaking capacitors (for now ill pretend the ecu isnt the problem).

now onto the wiring.

i replaced the necesary plugs (b1,m1,c1,etc). the car turns over but doesnt start. i confirmed the ECU has 12v constant (plug T pin 2 wire black/yellow). the question i have is, should i get power to pins 1 (black/red) and 3(black/orange) on the T connector of the ecu when i turn the ignition to the ON position? (i dont know much about the 1jz ecu) i confirmed the C1 plug is wired correctly but only the black/yellow wire has power (black/red and black/orange do not have power at the fuse box when the ignition is on) any ideas on whether this is normal or what potential issues i may have? i looked at the fuses and they all seemed good.

later today or tomorrow i will retest for spark to ensure thats not the issue
the fuel pump has the 12v mod so it turns on
the starter turns (engine cranks)

p.s. with the bad wiring i got from tweak and the time its taking, im trying to get it done myself so please dont make smart alec remarks about sending it to tweak :icon_razz

 

[suprachris]

so if im understanding this. the engine will crank just fine but wont fire? if this is the case are you sure you have a good map sensor? mine would not run with out the throttle slightly opened when i was missing my map.

 

[limitedgt4]

ill double check with a friends map sensor.

 

[hvyman]

the black red should have power when the ignition is on.

sounds like the igsw wire is not wired in. should be the gray wire on the engine harness side of the b1 connector. that will have 12v with ign on and then the ecu will power m-rel wire which is the black orange wire which powers the main relay which when powered up gives the black red wire 12v.

the black yellow wire is constant 12v battery voltage.

 

[limitedgt4]

Perfect. Thats exactly what i needed to know. Many thanks... looks like in 2016 one more 1kz powered mk3 will come back to life

 

[limitedgt4]

the black red should have power when the ignition is on.

sounds like the igsw wire is not wired in. should be the gray wire on the engine harness side of the b1 connector. that will have 12v with ign on and then the ecu will power m-rel wire which is the black orange wire which powers the main relay which when powered up gives the black red wire 12v.

the black yellow wire is constant 12v battery voltage.

so this is a wire i left and didnt connect to anything. on the diagrams it says pin 9 from the h1 (b1) square gray plug goes into pin 16 of the b1 yellow plug . but both diagrams say this is the check engine light. is this also the igsw?

the diagram listed pin 14 on the jza70 harness as the igsw wire which goes into pin 17 of the yellow plug harness. i did read somewhere on this forum that its ok to connect the black/orange wire from the b1 plug to the grey wire on the ecu plug (t) pin 13 which is the igws per the ecu diagram. i just want some reassurance before i fry the ecu up. could i also just feed any ign switched power to the gray wire on pin 13 of the t connector (on the ecu side)?

HTML Code:
pre89 1991
Pin # Pin # Function
1 1 A/C Water Valve VSV
2 B2 #17 L3 Signal ECT / ECU
3 B2 #18 L2 Signal ECT / ECU
4 B2 #19 L1 Signal ECT / ECU
5 3 FP Signal (Check Connector)
6 4 EFI Circuit Opening Relay Coil
7 5 A/T Circuit Opening Relay Coil
8 6 Fuel Pump Control Relay
9 7 Circuit Opening Relay B+
10 --Blank--
11 B2 #7 "N" Signal - A/T Indicator Switch
12 10 Neutral Start Switch
13 11 A/C Amplifier
14 B2 #6 TEMS Check Connector
15 8 NSW Switch to Cruise Control Clutch Switch (M/T)
16 9 Check Engine Light
17 14 Ignition B+
18 12 Theft Deterrent Horn Signal
19 B2 #4 Headlight Idle Up Signal
20 N/A Coil to Super Monitor Computer
21 N/A Super Monitor Computer
22 N/A Super Monitor Computer B-


from this site

http://www.toyota-supra.info/forums/105908-post1.html

 

[limitedgt4]

ok so i jumped the gray wire to a switched ignition source. the ecu now has power and i can hear the click sound of what i believe is the efi / main relay. the car doesnt turn on still, it just cranks.

this may be a dumb obvious question however previously ive been able to turn on an engine without connecting the knock sensors. is this required to be connected for the 1jz engine?

 

[f00g00]

so this is a wire i left and didnt connect to anything. on the diagrams it says pin 9 from the h1 (b1) square gray plug goes into pin 16 of the b1 yellow plug . but both diagrams say this is the check engine light. is this also the igsw?

No the check engine light is on the IG1 plug pin 19 to M1 pin 8.View attachment IG1(87-89).pdf

 

[limitedgt4]

Got it. Thanks

 

[limitedgt4]

No the check engine light is on the IG1 plug pin 19 to M1 pin 8.View attachment 77595

i hooked up the b1 pin 16 balck/orange wire to the grey wire but the black orange wire has no power and the ecu doesnt turn on like it did when i connected the grey wire straight to a switched ignition source. in short, those 2 wire dont go together and pin 16 on the b1 yellow plug does seem to be the check engine light as per the diagrams.

ive rewired the grey wire to a switched ignition source.

as promised i pulled the coils and attached the spark plugs and tested for spark but got non. i tested the power to the igniter a and its getting 12v. im now going to test the coil pack plugs.

any other suggestions on what could cause no spark?

things to know, engine was rebuilt and has started with a different harness as per my first post (unless ive damaged some electronics with the new harness, ill assume they all work.....for now)

coilpacks are not ripped.
igniter worked fine preiously.
crank sensor is good
cam sensors are good

im thinking its wiring related but not sure what wires to look for. before pluging the harness to the engine, i tested for continuity from the ecu plug to the igniter plug and from the igniter pug to the coilpack plugs. they all tested fine

 

[limitedgt4]

ok, so i tested the coil pack connectors. i get 12v on the black wire on all connectors but the wires that feed from the igniter (the yellow stripped wires) had no power. i tested the igniter connector for the ignition wires that come from the ecu and those had no power as well, which explains why there was no power on the second wire of the coil pack plugs.

it sounds like a bad ecu although there are no leaking capacitors or apparent issues with the ecu.

does anyone have any other thoughts on what could cause the 6 ignition (coil pack) wires to not have power?

 

[suprachris]

Dumb question, do you have the igniter bolted down, the head ground and block ground hooked up? Things I did to get mine to run were, jump the fuel pump, straight 12v. Also had to run my own starter wire from the chassis side of the harness to the switched 12v on the starter. Info I used to wire my jzx90 was on here. "How to wire a soared into a ma70" everything was pretty correct, the alternator plug is an oval plug. I got lucky and the colors matched. I also made a separate harness for the alternator to the fuse box. Mine will now run with no cel codes and all gauges work but speedometer.

 

[suprachris]

Also the only part of the harness I extended was for the fuel and gauges. I did not cut the ecu harness. It fits in its factory location just fine. Looks like crap under the hood be never the less it works. 1jz auto non vvti

 

[f00g00]

i hooked up the b1 pin 16 balck/orange wire to the grey wire but the black orange wire has no power and the ecu doesnt turn on like it did when i connected the grey wire straight to a switched ignition source. in short, those 2 wire dont go together and pin 16 on the b1 yellow plug does seem to be the check engine light as per the diagrams.

ive rewired the grey wire to a switched ignition source.

The HTML code for the diagram you are using from Toyota-supra.info is
wrong --->"16 9 Check Engine Light". (I can't find a 91 diagram to check 9)
it should be 16 16 IGSW (It is 16 for both 87 and 90)
You can see here on the 7M-GTE diagram
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=49
B1 pin 16 goes to IGSW on the ECU (this is the 90 diagram)
B1 pin 16 goes to IG S/W on the ECU (87 TEWD)
If you connected pin 9 IH1 to 16 B1 plug and do not have power then check your IGN fuse in the left kick panel.
The above diagram also shows the check engine light going through plug M1 pin 8 as stated before.
You should wait for your tweak harness.

 

[limitedgt4]

The HTML code for the diagram you are using from Toyota-supra.info is
wrong --->"16 9 Check Engine Light". (I can't find a 91 diagram to check 9)
it should be 16 16 IGSW (It is 16 for both 87 and 90)
You can see here on the 7M-GTE diagram
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=49
B1 pin 16 goes to IGSW on the ECU (this is the 90 diagram)
B1 pin 16 goes to IG S/W on the ECU (87 TEWD)
If you connected pin 9 IH1 to 16 B1 plug and do not have power then check your IGN fuse in the left kick panel.
The above diagram also shows the check engine light going through plug M1 pin 8 as stated before.
You should wait for your tweak harness.

your the man :love: you called it. blown fuse. ive looked in so many places the obvious things escape me :icon_razz the car is now all wired up properly and ecu turns on right. the car now show signs of life. it sputters and you can hear 1 or 2 cylinders firing :icon_bigg after i switch the ignition off the car sounds like its gonna start and runs for 2 seconds and shuts off.

the adventure continues


many thanks guys

 

[limitedgt4]

thanks a ton @f00g00 and @hvyman for all your input. you guys brought another 1jz MK3 Supra to life. im glad to announce the car is up and running and everything is working fine. it idles smooth and revs as it should. now to enjoy my car :love:

 

[suprachris]

Good to hear.