[cutlass supreme FE3]

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.

[3XTurboAgain]

code 34 could be vacuum leak going to the map sensor... maybe a cracked vaccum tube coming from your fuel regulator.

[cutlass supreme FE3]

thanks for the info.
now how do you reset the ECM without disconnecting the main battery? There is an aftermarket alarm and last time i did it the siren and car horn went off.

[3XTurboAgain]

im pretty sure you have to unhook the battery.

[cutlass supreme FE3]

Originally Posted by 3XTurboAgain

im pretty sure you have to unhook the battery.

okay will do the battery unhook

[pocket-rocket]

Originally Posted by cutlass supreme FE3

okay will do the battery unhook

I always just pull the ECM fuse beside the fuel pump relay for 15 seconds...

[cutlass supreme FE3]

Originally Posted by pocket-rocket

I always just pull the ECM fuse beside the fuel pump relay for 15 seconds...

i'll give your method a shot.

[cutlass supreme FE3]

it works and now i only get code 54

[pocket-rocket]

Originally Posted by cutlass supreme FE3

i'll give your method a shot.

I prefer it so I don't have to set the clock and all the other options in my stereo after clearing the ECM.

Maybe this post on yahoo answers will help:

http://answers.yahoo.com/question/in...6153042AAAXVQp

[cutlass supreme FE3]

Originally Posted by pocket-rocket

I prefer it so I don't have to set the clock and all the other options in my stereo after clearing the ECM.

Maybe this post on yahoo answers will help:

http://answers.yahoo.com/question/in...6153042AAAXVQp

thanks for the links.

the article noted that it can be either the fuel pump relay or the oil pressure switch.
I know where the relay is but do you have a picture where the oil pressure switch is? it states between the two cylinderhead valley underneath the thermostat?? I have the digital dash with the oil pressure gauge so do i have a two wire or three wire switch?
thanks in advance