code 22 and 31

[122578]

i was wondering if anyone has had these two codes together?

22 - temp sensor
31 - afm

the car runs great driving its just at idle were everything goes wrong.
after starting the car it runs good till the rpms return to normal after the choke lets go. then the af ratio goes rich, the idle is sporadic almost cutting off and codes 22 and 31.

already switched out the afm twice with known good ones. temp sensor reading fine. did a leak test but nothing.

any suggestions?

[a_sesshoumaru]

Ecu?

[supraman74]

Did you clear the codes each time you swapped afm's?
Check the wiring harness at each sensor also.
When you say "temp sensor reading fine" does that mean you ohm's tested the water temp sensor?

[122578]

Did you clear the codes each time you swapped afm's?
Check the wiring harness at each sensor also.
When you say "temp sensor reading fine" does that mean you ohm's tested the water temp sensor?

yes i cleared the codes every time.

i didnt check the ohms of the temp sensor. i cant find the info on what signals to check 4. i want to test the afm wires but dont know how.

[supraman74]

Water Temp
http://www.supra.co.nz/87tsrm/EFI/efi116.htm

AFM
http://www.supra.co.nz/87tsrm/EFI/efi98.htm

ECU voltage and ohm's testing
http://www.supra.co.nz/87tsrm/EFI/efi125.htm

I got the links from here:
http://www.supra.co.nz/87tsrm/index.htm

[122578]

thanks i really appreciate the help.

[122578]

turns out it was a recently replaced thermostat. i took it out and it ran fine. put it in again and problems came back.

thanks 4 your help.

[jetjock]

Say what? It's not possible for a thermostat to cause those codes...

[122578]

dont ask me i never have a reasonable problem.

[Shima]

maybe knocked some wiring out of place doing the thermostat and knocked it back after hehe?

[122578]

very possible. i checked all my wires when putting the new one back in. everything seems fine.

[supra87ken]

hi my supra dont have thermostat and it works very fine

[jdub]

hi my supra dont have thermostat and it works very fine

If you want to call "fine" staying in cold start enrichment for a very long time while your coolant take forever to get to ops temp (176 deg F). Not using a thermostat on an EFI car (like the Supra) is a very bad idea.

[sogi99]

there's a reason why the car has a thermostat in the first place. Otherwise, toyota engineers wouldn't have bothered to put one in there if it doesn't need. just my 2 cents