I have an 82 and I'm suspecting that the ECM emissions control module is not working. Any diagnostic techniques someone can recommend? If I unplug the ECM it as the same as it does plugged in. Starts fine runs great, shut down then it wont idle or start without holding the gassed peddle. After it cools down it will run fine again.

 

Can you clarify this sentence.



Doesn't the early Aisan carburetors use the Hot Idle Compensator on the carburetor? It's a thermostatic valve that aids in hot engine starts.

On my 87 carburetor, the casting is there but Toyota switched to a different method.

The only other thing I can think of for the ECM is the Fuel Cut Solenoid. You could test that.

 

Seems like he is saying his motor ran the same with the ecu in both conditions-plugged and unplugged. Neither one affected how it ran. Hence why he suspects a bad ecu

 

Yes it tuns the same with or without. I hard wired the cut solenoid already.

 

Well, the only other thing the ECM controls on the carburetor is the Outer Vent Control Valve (OVCV). That is only an emissions function, not a operational function.

On my '87 carburetor truck, sometimes the carb will flood as a result of gas leaking into the manifold and makes it hard to start. When that happens, the OEM owner's manual says to press the gas pedal all the way to the floor and hold it there untill the engine starts.

So I would say at this point is check the Hot Idle Compensator.


The ECM is not used to control or operate the ignition system. It does not regulate the fuel in the carburetor except for the Fuel Cut Solenoid. There are other things it controls, but from your first question, it does not seam to be the cause for what you are asking about.