Trouble Codes - Help!

[82much]

I need assistance with some trouble codes Im getting. Check Engine light comes on and off periodically on my 1991 3FE. I got 2 codes. 25 and 26.. I just need help on where to start.

25	Mixture control -continuously lean	Wiring, injector, H02S, ECT/VAF sensor, intake/fuel/ignition system, ECM
26	Mixture control -continuously rich	Wiring, injector, fuel system, cold start injector, H02S, ECT/VAF sensor, ECM

 

[Fj80oregon]

Download the fsm from the resource section and follow the trouble shooting procedures.

 

[82much]

Download the fsm from the resource section and follow the trouble shooting procedures.

So, I have the complete FSM and then some. I cannot find anything in the documents that reference any ODB I codes.

 

[ppc]

Fi or EFI section will have "Diagnostic Codes.

 

[Marvelicious]

So, I have the complete FSM and then some. I cannot find anything in the documents that reference any ODB I codes.

Which version of the manual did you grab? You would need one from a year that had OBD I. The 96 manual I have has an extensive section on diagnostics, but it only covers OBD2

 

[jonheld]

So, I have the complete FSM and then some. I cannot find anything in the documents that reference any ODB I codes.

From the 1991 Toyota FSM:

 

[jonheld]

FWIW, codes 25/26 are almost always faulty O2 sensors or associated wiring.

 

[82much]

Which version of the manual did you grab? You would need one from a year that had OBD I. The 96 manual I have has an extensive section on diagnostics, but it only covers OBD2

I have the 1991 FSM.

 

[82much]

From the 1991 Toyota FSM:

View attachment 3469364

View attachment 3469365

Perfect. Thank you. I have about 6 different folders with a lot of documents to go trough. I didnt see this one but I will double check.

 

[jonheld]

Perfect. Thank you. I have about 6 different folders with a lot of documents to go trough. I didnt see this one but I will double check.

The complete 1991 Toyota LC FSM is a 38MB single pdf file that is searchable. Same for the 1991 EWD which is a little over 3MB.

 

[IXsokudo]

The complete 1991 Toyota LC FSM is a 38MB single pdf file that is searchable. Same for the 1991 EWD which is a little over 3MB.

How can one obtain EWD for a 91 LC?

 

[jonheld]

How can one obtain EWD for a 91 LC?

FSM Scans

 

[IXsokudo]

FSM Scans

Thank You Sir