I have an 85 wagon, replaced timing belt and bent valves.
Put the car together, it started but started rough and
stumbling. Read computer codes: 12,23, and 31. They mean
bad tps, bad air flow meter, and bad a/c system. Put
a new tps, and a used AFM car still runs rough and refuses
to start. After changing TPS and used AFM code 12 went away
but 23 and 31 remain. I know I have fuel pressure and spark.
I also replaced injector connections (too brittle!!)

I did some research and there were some service bulletings
issued related to this problem. Unfortunately, I have been unable to locate them. I am still waiting for factory manual
too.

Any ideas anyone, or similar experience.

Thanks, this is my first post on the list. Have played with
other nissans but not wih maxima.
Thanks

 

I have a service manual for my 87 max and I don't see a listing for code 31 or 23. code 12 is the AFM but there isnot a listing for the other codes. Also when I put mine together I had problems too my advice is to check your ignition timing. It would could way to advanced or retarded causing the rough starting. I remember that there was a fuel injector recall for the 85-88 maxima's and 84-87 300zx's. If that hasn't been done to your car your local nissan dealer should do it for free. I suspect that your ignition timing is just off. There is nothing I hate more than having to mess with the distributor to get the timing right.

 

If the engine had been running OK before the belt broke, and you got a decent valve job when you replaced the valves it sounds like your timing belt bay be installed one tooth off. A compression guage will tell you if the vavle job was any good. I don't know of a way to check the cam/crank timing without removing covers.

 

I have checked compression, fuel pressure, firing and reset
timing belt twice. I did stopped by the dealer got a copy of
bulletin 96-032. They suggested me to give then VIN so as to
check for the injector fix recall. I suspect that the car may not had this done. That is exactly what I suspected, that injectors may not be spraying fuel at all.

Just to follow up in the previous answer, ecu codes are
printed on the computer.

I will work on the car this weekend.