sc2dave

Do I really need the ecm on my 87 22r? What does it control?

old87yota

Is your engine stock or modified?

If you no longer have the factory Aisan Carburetor and have replaced it with an aftermarket carburetor, than the Emissions Computer really can't do much as aftermarket carburetors simply cannot use any of the factory "emissions" equipment. The information below may or may not be useful if this is the case, and is the long answer to your question.





If the engine has the factory setup:

Is your truck Federal Emissions or California Emissions?

The factory 22R does not really have an engine computer. It is more of an Emission Control Computer, and that is what Toyota calls it.

If the engine is still stock (with the Aisan carburetor), than yes, the Emissions Computer is needed for proper function of the carburetor, particularly with the California Emissions Package. [You can make the factory carburetor run without all of the add-ons, but it won't work as well as it was designed].

The Emission Control Computer controls vacuum switching valves (VSVs) for the evaporative emissions system, the Cold Mixture Heater on the bottom of the intake (helps the fuel turn into vapor on cold engine), the fuel cut system [fuel cut switch and fuel cut solenoid] (prevents afterburning in the exhaust during deceleration). The Federal Emissions computer takes input from an engine coolant temperature switch, ignition signal for engine RPM, speed sensor in the gauge cluster and Over Drive switch for Automatic Transmissions.

If you have the California Emissions Package, you will have a larger computer that controls more Vacuum Switching Valves, and takes input from more sensors such as an oxygen sensor and vacuum switches.


One common misconception is that Toyota used this fairly complex system purely to pass emissions standards, and nothing else. Many people see the world "emissions", freak out, and have an urge to rip out anything even remotely related to that word.

What Toyota really did was to create a carburetor and a control system to work with the carburetor that made the engine run better in a wide variety of conditions. By having a better running engine under those conditions, Toyota was able to reduce emissions. It is this idea that made Toyota not have the "choked by emissions" problems that American cars had.