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I have a 1988 Oldsmobile Cutlass Supreme International with a 2.8 MFI motor.
The car has about 140,000 kilometers and I getting the idle to fluctuate up and down from 600 to 1100 in Park or in Drive with the brakes on.
Things that I replaced was A/C Delco Mass air flow, A/C Delco MAP sensor, and a Standard Engine Coolant sensor.
I have tested the TPS sensor and get 0.4 volts closed and 4.4 volts opened.
Jumping the ALDL connector i get
CODE 34
Trouble Code 34 indicates that the Manifold Absolute Pressure (MAP) sensor is detecting unusually high vacuum in the manifold. Code 34 will get set when:
* Engine RPM less than 700.
* Manifold pressure reading less than 13 kPa.
* Conditions met for .22 second.
OR
* Engine RPM greater than 700.
* Throttle angle over 20%.
* Manifold pressure less than 13 kPa.
* Conditions met for .22 second.
Possible causes include:
1. Faulty MAP-to-ECM connection
2. Defective MAP sensor
3. Defective ECM
Check the shop manual for details on vehicle specific MAP sensor applications.
CODE 45
Trouble Code 45 indicates that the O2 sensor is showing a persistently low exhaust oxygen content (rich), despite the efforts of the ECM to decrease injector on-time (thus decreasing fuel delivered). Integrator and BLM numbers may indicate < 128 by a substantial margin.
Code 45 is set when:
* O2 sensor voltage remains above .7 volt for 50 seconds
* engine has been running for 1 minute or more
* throttle is between 3 and 45 percent open
* system is running "Closed Loop"
Possible causes include:
1. O2 sensor defective or contaminated (if incorrect RTV sealant or too much RTV is used, this may happen)
2. Leaking fuel injectors
3. Fuel pressure too high
4. EMI interference from poor plug wires
5. Evaporative Emission system defect
6. TPS and/or EGR problem
Note: Presence of Code(s) 33 and/or 34 may indicate MAP problem. This should be the first suspect in the case of a Code 45 being set.
CODE 54
Trouble Code 54 indicates a low voltage at the fuel pump. If the voltage at terminal "A20" is less than 4 volts for .4 seconds since the last reference pulse was received, the code will be set.
Possible causes include:
1. Faulty fuel pump relay.
2. Faulty connection at ECM.
3. Faulty oil pressure switch.
4. Faulty ECM.
The car has about 140,000 kilometers and I getting the idle to fluctuate up and down from 600 to 1100 in Park or in Drive with the brakes on.
Things that I replaced was A/C Delco Mass air flow, A/C Delco MAP sensor, and a Standard Engine Coolant sensor.
I have tested the TPS sensor and get 0.4 volts closed and 4.4 volts opened.
Jumping the ALDL connector i get
CODE 34
Trouble Code 34 indicates that the Manifold Absolute Pressure (MAP) sensor is detecting unusually high vacuum in the manifold. Code 34 will get set when:
* Engine RPM less than 700.
* Manifold pressure reading less than 13 kPa.
* Conditions met for .22 second.
OR
* Engine RPM greater than 700.
* Throttle angle over 20%.
* Manifold pressure less than 13 kPa.
* Conditions met for .22 second.
Possible causes include:
1. Faulty MAP-to-ECM connection
2. Defective MAP sensor
3. Defective ECM
Check the shop manual for details on vehicle specific MAP sensor applications.
CODE 45
Trouble Code 45 indicates that the O2 sensor is showing a persistently low exhaust oxygen content (rich), despite the efforts of the ECM to decrease injector on-time (thus decreasing fuel delivered). Integrator and BLM numbers may indicate < 128 by a substantial margin.
Code 45 is set when:
* O2 sensor voltage remains above .7 volt for 50 seconds
* engine has been running for 1 minute or more
* throttle is between 3 and 45 percent open
* system is running "Closed Loop"
Possible causes include:
1. O2 sensor defective or contaminated (if incorrect RTV sealant or too much RTV is used, this may happen)
2. Leaking fuel injectors
3. Fuel pressure too high
4. EMI interference from poor plug wires
5. Evaporative Emission system defect
6. TPS and/or EGR problem
Note: Presence of Code(s) 33 and/or 34 may indicate MAP problem. This should be the first suspect in the case of a Code 45 being set.
CODE 54
Trouble Code 54 indicates a low voltage at the fuel pump. If the voltage at terminal "A20" is less than 4 volts for .4 seconds since the last reference pulse was received, the code will be set.
Possible causes include:
1. Faulty fuel pump relay.
2. Faulty connection at ECM.
3. Faulty oil pressure switch.
4. Faulty ECM.
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