Running rough hot code 31 - Toyota Nation Forum : Toyota Car and Truck Forums

eppoh · 07-28-2010, 06:18 PM

Helping a friend here. He bought a 95 Camry and put a used engine in it. The old one had broke a connecting rod. It ran okay for a few minutes, but then started running rough and died. Now it will not idle and runs only at about 1200 rpm with 3/4 throttle. The exhaust gets cherry red. It is throwing a code 31. I'm not a Toyota guy, so any help appreciated. ( Okay my wife drives an Avalon, but I never have to work on it)

eppoh · 07-30-2010, 07:05 AM

bump for help pls

71Corolla · 07-30-2010, 08:30 AM

Was the used engine known to be running properly before it was installed? My first thought is bad crank to camshaft timing. Bad ignition timing can also cause this, a clogged exhaust is another possibility, as well as vacuum leaks. Don't run the engine like that, the heat can burn up the combustion chamber very quickly, even burn holes in the pistons depending on what is wrong.

Jason.MZW20 · 07-30-2010, 08:56 AM

Code 31 refers to the MAP sensor circuit.