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10 Cards in this Set
- Front
- Back
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The port fuel injection system components includes |
1. Powertrain control module 2. Fuel pump 3. Fuel injectors 4. Relays 5. Inputs to support Fuel control (IAT, ECT, CKP, CMP, APS, TPS, MAF, MAP, Air-fuel ratio sensor) |
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The PCM monitors sensors |
Input data and uses fuel data mapping to determine injector pulse width(on-time) to deliver the necessary amount of fuel. |
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The PCM monitors engine load based on the following high-authority inputs: |
1. Engine rpm crankshaft sensor 2. Engine coolant sensor 3. Engine load from throttle position and either MAF or MAP |
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A higher level of oxygen in the exhaust |
indicates the mixture is leaner than the target |
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A lower level of oxygen in the exhaust |
indicates the mixture is richer than the target |
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Several input sensors provide data that allow PCM to adjust fuel delivery (high authority sensors |
1. ECT 2. Engine speed from CKP 3. Engine load calculation from the TPS and MAF or MAP |
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Low authority sensors provide additional data for the PCM to calculate the fuel injector on-time |
1. IAT 2. CMP 3. APS |
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IAT/ECT sensors compensate for very cold or hot ambient air and for the temperature of the engine |
A cold engine requires more fuel ( a richer mixture) to start and run, as gasoline does not vaporize well at cold temperature |
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CKP/CMP |
provide data on engine speed and what cylinder is on the intake stroke, so the fuel injectors can be operated for each cylinder as the intake valve is opening |
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The air fuel ratio sensor |
Provides feedback to the PCM on how well the fuel delivered was burned in the engine. This allows the PCM to add or subtract fuel by controlling injector on-time to achieve the desired air fuel ratio. Technicians can view air fuel ratio using the fuel trim data |
