It still wont start!!! HELP!

[JohnRardin]

I've been trying for about a week to get my 7mgte to start, but the ECU isnt allowing it to. I've been told to jiggle the cam position sensor wires, but that didnt work. I tried replacing it today but it cranked irregularly so I put everything back the way it was. My mechanic says its the crank position sensor, but I've been somewhat confused on its location. Heres the codes I'm getting:

12 RPM Signal


Diagnosis

* No "NE" or "G" signal to ECU within 2 seconds after engine has been cranked.

Trouble Area

* Distributor, or CPS, circuit
* Distributor or CPS
* Starter signal circuit
* ECU

21 Oxygen Sensor Signal


Diagnosis

* Detection of oxygen sensor deterioration.

Trouble Area

* Oxygen sensor circuit
* Oxygen sensor
* ECU

31 Air Flow Meter Signal


Diagnosis

* (7M-GE) Open circuit in VC signal or short circuit between VS and E2 when idle contacts are closed.
* (7M-GTE) Open or short circuit in air flow meter signal.

Trouble Area

* Air flow meter circuit
* Air flow meter
* ECU

34 Turbocharger Pressure


Diagnosis

* The turbocharger pressure is abnormal.

Trouble Area

* Turbocharger
* Air flow meter
* ECU
* Intercooler system


42 Vehicle Speed Sensor Signal


Diagnosis

* No "SPD" signal to ECU for 8 seconds when engine speed is between 2,500RPM and 4,500RPM (7M-GE) or 4,000RPM (7M-GTE) and coolant temp is below 80°C(176°F) and neutral start switch is off.

Trouble Area

* Vehicle speed sensor circuit
* Vehicle speed sensor
* ECU


I just bought the repair manual and a multimeter but I'm almost completely lost at this point. I've replaced just about everything on my supra before but the solution to this eludes me. I need to fix it ASAP, where do I start?

PLEASE HELP!!!

 

[Fletch124]

You could try hardwiring the CPS, completely eliminates the connector problem.

Replace the AFM.

Replace Vehicle Speed Sensor.

 

[JohnRardin]

You could try hardwiring the CPS, completely eliminates the connector problem.

Replace the AFM.

Replace Vehicle Speed Sensor.

how do i hardwire it?

 

[Supraboy89]

I've been trying for about a week to get my 7mgte to start, but the ECU isnt allowing it to. I've been told to jiggle the cam position sensor wires, but that didnt work. I tried replacing it today but it cranked irregularly so I put everything back the way it was. My mechanic says its the crank position sensor, but I've been somewhat confused on its location. Heres the codes I'm getting:

12 RPM Signal


Diagnosis

* No "NE" or "G" signal to ECU within 2 seconds after engine has been cranked.

Trouble Area

* Distributor, or CPS, circuit
* Distributor or CPS
* Starter signal circuit
* ECU

21 Oxygen Sensor Signal


Diagnosis

* Detection of oxygen sensor deterioration.

Trouble Area

* Oxygen sensor circuit
* Oxygen sensor
* ECU

31 Air Flow Meter Signal


Diagnosis

* (7M-GE) Open circuit in VC signal or short circuit between VS and E2 when idle contacts are closed.
* (7M-GTE) Open or short circuit in air flow meter signal.

Trouble Area

* Air flow meter circuit
* Air flow meter
* ECU

34 Turbocharger Pressure


Diagnosis

* The turbocharger pressure is abnormal.

Trouble Area

* Turbocharger
* Air flow meter
* ECU
* Intercooler system


42 Vehicle Speed Sensor Signal


Diagnosis

* No "SPD" signal to ECU for 8 seconds when engine speed is between 2,500RPM and 4,500RPM (7M-GE) or 4,000RPM (7M-GTE) and coolant temp is below 80°C(176°F) and neutral start switch is off.

Trouble Area

* Vehicle speed sensor circuit
* Vehicle speed sensor
* ECU


I just bought the repair manual and a multimeter but I'm almost completely lost at this point. I've replaced just about everything on my supra before but the solution to this eludes me. I need to fix it ASAP, where do I start?

PLEASE HELP!!!

when you replaced the cps did you time it correctly

 

[JohnRardin]

when you replaced the cps did you time it correctly

apparently not because it wasnt cranking smoothly.....scared me so I just put it back the way it was before. Still no help though

 

[Supraboy89]

apparently not because it wasnt cranking smoothly.....scared me so I just put it back the way it was before. Still no help though

try this.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=IG&P=24

if it wasnt cranking smoothly the ignition timing was off

 

[JohnRardin]

try this.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=IG&P=24

if it wasnt cranking smoothly the ignition timing was off

Yea thats definately it. I just reinstalled the replacement CPS and checked the codes again and now all I'm getting is a code 14: ignition problem.

What could've suddenly stopped working in the ignition system? the engines got 50k miles but the car is about 175k so I'm not too surprised. What should I check first?

 

[Idealsupra]

ok changing timing wouldnt eliminate half of the codes you listed...

start over.

clear ALL codes.... then crank car over and then pull the codes and post what is left on there.

also when you are trying to start it, its cranking correct? its just not STARTING?

 

[Frank Rizzo]

My mechanic says its the crank position sensor

There is no crank position sensor on a 7M. The JZ's have them. But you clearly stated you own a 7M.

 

[JohnRardin]

There is no crank position sensor on a 7M. The JZ's have them. But you clearly stated you own a 7M.

Actually I've had to do a lot of research on this one. On the 7M the CPS is both the cam and crank position sensor. There's been so much confusion on this because all modern engines have need to know crank position and obviously both are called a CPS.

 

[JohnRardin]

ok changing timing wouldnt eliminate half of the codes you listed...

start over.

clear ALL codes.... then crank car over and then pull the codes and post what is left on there.

also when you are trying to start it, its cranking correct? its just not STARTING?

As I said before, I replaced the CPS and reset the ECU and now all 5 of the codes I was getting are cleared. Unfortunately now I have a code 14 ignition problem. Does this make any sense to anyone else, cuz its confusing the hell outta me.

Where can I start?

 

[88supraFAST1]

i would check grounds it sounds like you have an intermittent short or something because if you just changed the CPS that shouldn't make the codes go away and then give you a new one. somethings really not right i would also check over the wiring harness make sure nothing is broken or heat soaked.

 

[jetjock]

Did you try searching for code 14? It's been explained many times. It's in the manual too.

Means there is no spark or there is spark but the ECU isn't receiving confirmation of it on signal wire IGf. As long as that happens the fuel injectors will not operate. Trouble areas are usually the CPS, igniter, coil pack primary circuit, or wiring. Basically anything that prevents the packs from firing or, if the packs do fire, prevents IGf from being sent back to the ECU.

 

[Idealsupra]

does the tach bounce when you are cranking?

 

[JohnRardin]

Did you try searching for code 14? It's been explained many times. It's in the manual too.

Means there is no spark or there is spark but the ECU isn't receiving confirmation of it on signal wire IGf. As long as that happens the fuel injectors will not operate. Trouble areas are usually the CPS, igniter, coil pack primary circuit, or wiring. Basically anything that prevents the packs from firing or, if the packs do fire, prevents IGf from being sent back to the ECU.

Haha yea man...I know. I'm just trying to be as basic as I can in these responses. I have the manual and I've read all this stuff many times I just haven't ever done any of this electrical stuff before. Where can I check? I have the manual and a multimeter but, like I said, Im a complete rookie when it comes to any of this electronic stuff.

What confuses me is the tach doesnt bounce after replacing the CPS which means somethings still not working. My guess is that since theres an ignition short, the ECU stops there; which explains the other codes disappearing.

Strangest of all, just for kicks I reset the ECU and checked codes and I don't have any!!!! The CEL just blinks.

wtf?

 

[Supraboy89]

check the wires on the ignition module on the driverside fender.

 

[Idealsupra]

If i were you I would look into the wires for the cps... ill bet you could shake them around a bit and have it work... they get brittle and the connections become corroded etc.

 

[JohnRardin]

If i were you I would look into the wires for the cps... ill bet you could shake them around a bit and have it work... they get brittle and the connections become corroded etc.

Yea thats what everyone says. I hope you're right but I've definitely tried that multiple times with multiple CPSs. What else can I try?

 

[Supraboy89]

Yea thats what everyone says. I hope you're right but I've definitely tried that multiple times with multiple CPSs. What else can I try?

when you are tryin to start it does it kinda spit a little like the timing is off. I am not sayin your timing is off just need to what sounds you are hearin when you are tryin to start it. I have cps wiring probs to when mine acts up it will spit when i try to start it. other than that check your ignition module on the fender it could be bad.

 

[JohnRardin]

when you are tryin to start it does it kinda spit a little like the timing is off. I am not sayin your timing is off just need to what sounds you are hearin when you are tryin to start it. I have cps wiring probs to when mine acts up it will spit when i try to start it. other than that check your ignition module on the fender it could be bad.

Yea I'd say I didnt quite get the CPS in right so the timing might be a little off but it should start. I hardwired the ground from the battery to the igniter and then to the manifold ground.

Heres what I've figured out:

Still getting an Ignition code
The tach bounces.- CPS works
The fuel rail has pressure- fuels workin
The fuel pump cuts on.
The spark plugs get spark- somethin's definately workin (??)

STRANGEST OF ALL

when cranking I can hear it barely fire a couple times.

How can I get fuel and spark and not start? The engine runs great, it just stopped starting one day.

again, WTF?!!