1. Sensors: The ECU receives information from various sensors, such as the throttle position sensor, air flow meter, and crankshaft position sensor.
2. Calculations: Based on this information, the ECU calculates the required amount of fuel for optimal combustion.
3. Pulse Signal: The ECU then sends a specific electrical pulse to the fuel injectors.
4. Injector Activation: The fuel injector, which is essentially an electronically controlled valve, opens for a precise duration based on the ECU's pulse signal.
5. Fuel Delivery: Fuel is injected into the intake manifold during this brief opening period.
Important Notes:
* The ECU's logic and the duration of the injector pulse are determined by the specific model year and engine configuration.
* There are also dedicated injector drivers that may be present in some models, which act as intermediaries between the ECU and the injectors, amplifying the signal for reliable operation.
To diagnose an injector pulse issue:
* Inspect the wiring: Ensure the wiring to the injectors and the ECU is intact and free from corrosion.
* Check for continuity: Test the wiring to confirm that there is a complete electrical circuit from the ECU to each injector.
* Use a multimeter: Measure the voltage and pulse width at the injector connectors. This can help pinpoint whether the signal is reaching the injectors and if it's the correct pulse duration.
* Consult a repair manual: Refer to a specific repair manual for your 1988 Toyota pickup model for detailed information on testing and diagnosing fuel injector problems.
Remember, diagnosing electrical issues in an automobile can be complex. If you're not comfortable working on electrical systems, it's best to consult a qualified mechanic.
