Code 12 and no spark no start

[89 Black Beauty]

Driving down the Hwy and have about 20kms on rebuilt engine breaking it in.

Car dies, cranks but will not start.

After much trouble shooting this is what i've found;
remember NO spark
Igniter is good
Main relay is good (tried both on friends car)
Tried a known good CPS X 2

When i turn key on, tach does nothing however when i unbolt igniter from body then tach blips when ign is turned on. When i get no tach signal the AC on multimeter registers 0.1-0.3, when i un ground igniter i get 21-24.this is the strangest thing, because normally it should be grounded so why am, i getting signal when it is not?

Next thing i will be trying double checking coilpack resistance and grounding the coilpack plate, allthough ive had the car running without this grounded in the past but may as well try it all.
Will also try a different ecu.
CODE 12!! grr, will this shut off spark or is no spark a seperate issue?

thanks all help me i want to drive new motor!!!!!!!!!!!!!!!! frustration is to the max!!

 

[Kckazdude]

Code 12
No 'NE' of 'G' signal to ECU within 2 seconds after engine has been cranked.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=26

I am going to say your CPS wiring is bad. Read here for more information.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=IG&P=3

 

[89 Black Beauty]

I have no other electronics added, still code 12 and no spark, CPS wires are resoldered, coilpack plate is grounded, resistance of coils checks out, igniter good, main relay good, tach does nothing when ignition turns on.
what else to look for?

 

[Kckazdude]

Tach wont do anything until you correct the problem that is causing the code 12. You are not getting a signal from the CPS to the ECU for some reason. Main relay, coils and igniter mean squat for now. Try Ohming out the circuit from the CPS to the ECU.

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=040

 

[jdub]

Wiggle the CPS wires while a helper starts the car...make sure the battery is fully charged.

 

[89 Black Beauty]

Tach wont do anything until you correct the problem that is causing the code 12. You are not getting a signal from the CPS to the ECU for some reason. Main relay, coils and igniter mean squat for now. Try Ohming out the circuit from the CPS to the ECU.

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=040

You're talking about checking continuity? i've tested most wires, ill do the rest next time i work on it.
I might try running my own wires to see if the signal will get there.
Possibly a new ECU

jdub, it's not those wires... i've tried it many times

 

[Nghty89]

I am getting something similar, but cannot check codes, something with my terminal where the pins are too far down to attach a wire to see the codes...

Anyways, the engine cranks, very healthy, no spark, no power to the igniter when I check with a multimeter. I will see if wiggling the wires will help.

It ran fine the other night except for #6 spark wire popping off several times and arching on the highway, but it was ok after putting it back on. Woke up the next morning to drive to work and nothing. Just sits there and cranks... I'm almost lost. Tried replacing igniter and coil pack. I will be watching this thread to see what happens.

 

[89 Black Beauty]

damn sounds like youre in the same boat as me, your cps plug might be loose or dirty, i've had this issue in the past and that's all it was but now i'm not so sure. im thinking ECU.

Ill post an update when i get more info.

 

[89 Black Beauty]

soi checked continuity between all the wires in the diagram http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=40 and everything checks out so im pretty damn sure its ECU, i dont' know what else it can be.
Will let you know when i get the ECU

 

[89 Black Beauty]

new ECU in and it is not the answer.
I'll have to guess it's something with the engine harness, dare i pull it out and check every wire one by one? OH GOD!
BTW this is the first time i'll ever say this in all the years, i hate my supra right now.

 

[jdub]

Did you check the CPS wires running across the top of the cam back plate?
I've seen them get quite brittle and crack due to heat over the years in this area.

 

[89 Black Beauty]

yeah i have, i've actually got 4 new wires running from CPS to ECU in plance of factory wiring and still code 12

 

[Zumtizzle]

i have a feeling you've crossed said wires somewhere.

Are you dead on or off by 180?

Edit: No spark, test the ignitor?

 

[89 Black Beauty]

no crossed wires, black, blue, red, yellow.

what 180 are yout alking about, the CPS on the cams?
When i turn ignition on the tach does not jump a bit.
Checked continuity between;
Ignitor-Coilpacks =good
ignitor-ecu=good
cps-ecu=good (before and after running new wires)

 

[jetjock]

How many times do I have to say it: the ECU does not deal in resistance...

 

[89 Black Beauty]

meaning what?

if there are wires ran to the ECU then the purpose is to carry a signal, you check to see if that wire is in fact carrying the signal.

 

[jetjock]

Exactly. The problem is nowhere in the thread have I seen you do that. Does the TSRM say "No continuity signal to ECU within 2 seconds after engine has been cranked"?

Have you checked for NE and G signals with a minimum of 1 volt p/p coming out of the CPS? Have you checked the CPS pickups or the common wire to each in the CPS? Have you even taken the cover off and looked inside? I don't see where you did. Instead you swapped the ECU and considered pulling out the engine harness. That's brilliant. Maybe you should jack the radiator cap up and roll another car under it...

 

[89 Black Beauty]

We don't all have the experience you have, it may be black and white for you but to others its not that easy, this is why we are here to learn and help each other.

i'm sorry i dont know as much as you but when you're in a frustrating situation you try what you can to fix it, and it dosen't help to have you firing your mouth off.

 

[Nghty89]

Damn... well, moving on.

89BB- got it fixed. Turned out the car now, all of a sudden after running for a year without them, wanted the ground wires for the coil pack, and the igniter. Take the cover off of the cps and see where things are. Don't forget to set TDC first. I was 180 degrees off (the slot farthest to the right on the cps should be line up towards the top. It's easy to pull out and correct, but dont pull too far. You also have to go a little farther beyond since it is not a straight gear, it will slip back a little counter-clockwise.)
I do have to say though, it is always a good idea (same for computers too, that's where I first learned this) to check the easiest issues first. Never assume the worst unless you know for a fact and there is irrefutable evidence. Good luck man, I'll let you know if I think of anything.

 

[89 Black Beauty]

well thats good to hear you worked things out, i just came back from looking at it and found out a few things that i will not post up until it's resolved so as to not lead people in the wrong direction!