20 Most Recent
1991 Chevrolet Lumina Questions & Answers
Engine stalls driving down the road or on take
Trouble Code 42 indicates that there may be a malfunction in the
Electronic Spark Timing (EST) system. During cranking, the timing is
controlled by the ignition module and the ECM grounds the EST line. It
expects to see no activity on this line at this time. When the ECM
enters EST mode, it applies +5 volts to the BYPASS line and expects to
see voltage variations on the EST line.
Reasons for the ECM to set Code 42:
1. System in BYPASS mode (i.e. EST line supposedly grounded) but activity sensed on EST line
2. System in EST mode (i.e. BYPASS line driven with +5 volts) but no activity seen on the EST line
Possible causes include:
1. BYPASS line is open or grounded
2. EST line is open or grounded
3. Poor connections between ignition module and ECM
4. Poor routing of EST harness and/or poor quality ignition wires (EMI induced electrical noise
5. Faulty or incorrect ignition module
6. Faulty ECM
7. Faulty Pick Up Coil
8. Faulty Ignition Control Module
9. Faulty Crank Sensor or the Crank Sensor magnet probe could be cracked
91 Lumina crank no start.
If cleaning the injectors got it running and not it won't start I'd look at something contaminating the injectors, try recleaning again and see if it starts, if it does clean the fuel system
91 Lumina won't stay running; see lots of same question for same car but no problem solvers....Please help.
On electronic fuel injection pumping an pumping an pumping the gas pedal does nothing without the engine running ! Pushing the gas pedal to the floor will cause the PCM - engine computer to go into clear flood mode .
You have some very interesting ideas here , but not really how it works or is !
The vehicle will go into closed loop fuel control when the engine coolant temp reaches a definded temp an the O2 sensor get hot.
She would run for a couple minutes and die which is open loop when running, closed loop is when the sensors kick and it would die. Pulled spark plugs, they were black meaning no spark. Can only be 2
Black spark plugs indecate a rich condition , over fueled , wet spark plugs indecate no spark .
Gas gage not working
Maybe a problem with instrument cluster?
Usually the circuit works off resistance to ground. The sending unit in gas tank provides resistance to ground. The signal wire for fuel gage is a purple wire, if goes to fuel pump wiring connector. With key on, use digital multimeter, check for voltage. If no voltage, either problem with wiring circuit or instrument cluster. W/0 looking at instrument cluster, I don't know if you can replace gage itself w/o replacing instrument cluster?
If voltage on the purple wire, ground it, while a helper watches the gage, if the gage starts reacting, then check the grounds for fuel pump wiring connector, if that checks ok, suspect the fuel pump sending unit has a problem.
Speedometer not working
Rerplace the speedometer cable as well as the speedometer,if it still does not work,chck the fuses!
Speedometer does not work
Cant be sure but if its 91 its probably mechanical.check for cable going gearbox not wire cable probably inside cable broken or drive in gearbox
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