Throwing Codes 12,31,51 Help

[frontierguy25]

Ok Guys,

I took my son to get our haircuts this morning and everything was fine, it is about a mile from our house and I didn't drive through any water. When we get out, I go to start my car and it dies like 3 times. I give it some gas and it goes, but like I have an IC pipe loose, I did a brief check and it all looked ok when I got home.

12-Is RPM signal
31-Is AFM signal
51-Is a notorious pain in the ass

Does anyone know of a good way to check these? This is my daily so any help would be greatly appreciated.

Now that I think about it could it be something with my SAFR?

 

[Fletch124]

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


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
REPLACE AFM



51 Switch Signal

Diagnosis
No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check.
Trouble Area
A/C switch circuit
A/C switch
A/C amplifier
Throttle position sensor circuit
Throttle position sensor
ECU

 

[Quin]

12 Could be CPS wires, 31 could be a bad AFM or AFM wires, 51 is most likely your TPS. There are ways to test your TPS in the TSRM, if you do a bit of searching here or reading there you should find it. I don't have any advice on the AFM except swap it with a known good one and see if it goes away. With the motor running, wiggle the wires coming off the CPS. If it changes anything, you need to rewire it =]

 

[Nick M]

Does it start normal now? Or does it stall if you don't gas it?

You need to tighten the intercooler hose. Or anthing between the airlfow meter and throttle body.

Do that before the codes.

 

[frontierguy25]

Ok guys, I figured out 2 of the codes. 12 and 31, I got some electrical cleaner and sprayed the CPS connection and the AFM Connection, pulled the EFI, and plugged everything back together then put the EFI back and and WALA it works. I have a new harness I bought 2 years ago from champion so I new it wasn't the harness, it was just my dirty engine bay. I found the thread on 51 so I'll fix that next.

Thanks Guys

 

[89 Black Beauty]

does having code 12 mean the car will not start as long as youa re throwing that code?

I was driving my rebuilt engine and about 20km's on the motor the car died on hwy. it would not start and im throwing a 12.