engine problems, need help!!!
06-24-2003, 10:39 PM
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engine problems, need help!!! at about 200-2200 rpms, by car jerks and tugs pretty bad. even revving through there are pops and hesitations in the exhaust. i changed my plugs and the entire passenger side bank plugs were black, the drivers side plugs were fine. so i changed them all and my car still does it! is there something beyond plugs? any info will help, thanks. i have msd wires and bosch platinum plugs.
06-25-2003, 10:04 AM
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Re: engine problems, need help!!! I seem to notice that the push rods in the pontiacs seem to bend alot. Had 1 last year doing the same thing as yours. Try a pressureized injector flush first then go looking inside at the push rods. Same car also had a cracked rearend cage, helical gears i think they are called and that caused the jerking aswell. The guy told me that he let it go WOT on the back roads and that's when he noticed all the problems. 
. Do a compression test and see what happens.
. Do a compression test and see what happens.
06-25-2003, 02:00 PM
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Re: engine problems, need help!!! thanks for the replies guys, would the ignition module cause the passenger side plugs to go bad but the drivers side to be fine?
06-25-2003, 08:31 PM
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Re: engine problems, need help!!! Powertrain Control Module (PCM) Description
The Powertrain Control Module (PCM) is designed to maintain exhaust emission levels while maintaining excellent driveability and fuel efficiency. The PCM controls the following operations:
The fuel control
The ignition control (IC)
The knock sensor (KS) system
The automatic transmission shift functions
The manual transmission 1-4 Upshift and Reverse Inhibit
The cruise control enable, if the vehicle has this equipment
The generator
The evaporative emission (EVAP) purge
The A/C clutch control
The cooling fan control
The secondary air injection (AIR)
The exhaust gas recirculation (EGR)
The on-board diagnostics for the powertrain functions
Powertrain Control Module
The powertrain control module (PCM) is located in the engine compartment. The PCM is the control center of the vehicle.
The PCM constantly monitors the information from various sensors, and controls the systems that affect vehicle performance and the emissions. The PCM also performs the diagnostic functions for those systems. The PCM can recognize operational problems and will alert the driver through the Malfunction Indicator Lamp (MIL) when a malfunction occurs. When the PCM detects a malfunction, the PCM stores a diagnostic trouble code (DTC), which will help to identify the problem areas. This process helps the technician in making repairs.
The PCM supplies either 5 volts or 12 volts in order to power the various sensors or switches. This is done through resistances in the PCM. The resistance is so high in value that a test lamp will not illuminate when the lamp is connected to the circuit. In some instances, even an ordinary shop voltmeter will not give an accurate reading because the resistance is too low. Therefore, a digital voltmeter (DMM) with a minimum of 10 megaohms input impedance is required in order to ensure accurate voltage readings.
The PCM controls output circuits such as the injectors, the IAC, and the cooling fan relays by controlling the ground or the power feed circuit through transistors or with an output driver module.
Torque Management
Torque management is a function of the PCM that reduces engine power during certain conditions. Torque management is performed for the following reasons:
In order to prevent over stressing the powertrain components
In order to prevent damage to the vehicle during certain abusive maneuvers
In order to reduce the engine speed when the IAC is out of the normal operating range
The PCM monitors the following sensors and engine parameters in order to calculate the engine output torque:
The air/fuel ratio
The mass air flow
The manifold absolute pressure
The intake air temperature
The spark advance
The engine speed
The engine coolant temperature
The A/C clutch status
The PCM monitors the torque converter status, the transmission gear ratio, and the engine speed in order to determine if torque reduction is required. The PCM retards the spark as appropriate, in order to reduce the engine torque output if torque reduction is required. The PCM also shuts off the fuel to certain injectors in order to reduce the engine power in the instance of an abusive maneuver.
The following are instances when an engine power reduction is likely to be experienced:
During transmission upshifts and downshifts
During heavy acceleration from a standing start
If the IAC is out of the normal operating range
If the driver is performing harsh or abusive maneuvers, such as shifting into gear at high throttle angles or shifting the transmission from reverse to drive in order to create a rocking motion.
The driver is unlikely to notice the torque management actions in the first 2 instances. The engine power output will be moderate at full throttle in the other 2 instances.
The PCM calculates the amount of spark retard that is necessary to reduce the engine power by the desired amount. The PCM disables the fuel injectors for cylinders 1, 4, 6, and 7 if an abusive maneuver occurs.
PCM Function
The PCM supplies a buffered voltage to various sensors and switches. The PCM controls most components with electronic switches which complete a ground circuit when the switches are turned ON.
PCM Service Precautions
The PCM is designed to withstand the normal current draws that are associated with vehicle operations. Avoid overloading any circuit. When you test for opens or for shorts, do not ground any of the PCM circuits unless you are instructed. When you test for opens or for shorts, do not apply voltage to any of the PCM circuits unless you are instructed. Test these circuits with a digital voltmeter only, while the PCM connectors remain connected.
Aftermarket Add-On Electrical And Vacuum Equipment
Aftermarket electrical and vacuum equipment is defined as any equipment that connects to the vehicle's electrical or vacuum systems that is installed on a vehicle after the vehicle leaves the factory . No allowances in the vehicle design have been made for aftermarket equipment.
Notice
Do not attach add-on vacuum operated equipment to this vehicle. The use of add-on vacuum equipment may result in damage to vehicle components or systems.
Notice
Connect any add-on electrically operated equipment to the vehicle's electrical system at the battery (power and ground) in order to prevent damage to the vehicle.
Even if add-on electrical equipment is installed to strict guidelines, this equipment may still cause the powertrain system to malfunction. Equipment that is not connected to the vehicle's electrical system, such as portable telephones and radios, can also cause a malfunction. The first step in diagnosing any powertrain problem is to eliminate all aftermarket electrical equipment from the vehicle. If the problem still exists, diagnose the problem in the normal manner.
Engine Controls Information
The driveability and emissions information describes the function and operation of the PCM.
The engine controls information contains the following:
The component locations
The wiring diagrams
The PCM terminal end views and the terminal definitions
The Powertrain On-Board Diagnostic (OBD) System Check
The Diagnostic Trouble Code Tables (DTCs)
The component system includes the following items items:
The component and circuit description
The on-vehicle service for each sub-system
The functional checks and the diagnostic tables
The DTCs also contain diagnostic support information containing circuit diagrams, circuit or system information, and helpful diagnostic information.
Maintenance Schedule
The Powertrain Control Module (PCM) is designed to maintain exhaust emission levels while maintaining excellent driveability and fuel efficiency. The PCM controls the following operations:
The fuel control
The ignition control (IC)
The knock sensor (KS) system
The automatic transmission shift functions
The manual transmission 1-4 Upshift and Reverse Inhibit
The cruise control enable, if the vehicle has this equipment
The generator
The evaporative emission (EVAP) purge
The A/C clutch control
The cooling fan control
The secondary air injection (AIR)
The exhaust gas recirculation (EGR)
The on-board diagnostics for the powertrain functions
Powertrain Control Module
The powertrain control module (PCM) is located in the engine compartment. The PCM is the control center of the vehicle.
The PCM constantly monitors the information from various sensors, and controls the systems that affect vehicle performance and the emissions. The PCM also performs the diagnostic functions for those systems. The PCM can recognize operational problems and will alert the driver through the Malfunction Indicator Lamp (MIL) when a malfunction occurs. When the PCM detects a malfunction, the PCM stores a diagnostic trouble code (DTC), which will help to identify the problem areas. This process helps the technician in making repairs.
The PCM supplies either 5 volts or 12 volts in order to power the various sensors or switches. This is done through resistances in the PCM. The resistance is so high in value that a test lamp will not illuminate when the lamp is connected to the circuit. In some instances, even an ordinary shop voltmeter will not give an accurate reading because the resistance is too low. Therefore, a digital voltmeter (DMM) with a minimum of 10 megaohms input impedance is required in order to ensure accurate voltage readings.
The PCM controls output circuits such as the injectors, the IAC, and the cooling fan relays by controlling the ground or the power feed circuit through transistors or with an output driver module.
Torque Management
Torque management is a function of the PCM that reduces engine power during certain conditions. Torque management is performed for the following reasons:
In order to prevent over stressing the powertrain components
In order to prevent damage to the vehicle during certain abusive maneuvers
In order to reduce the engine speed when the IAC is out of the normal operating range
The PCM monitors the following sensors and engine parameters in order to calculate the engine output torque:
The air/fuel ratio
The mass air flow
The manifold absolute pressure
The intake air temperature
The spark advance
The engine speed
The engine coolant temperature
The A/C clutch status
The PCM monitors the torque converter status, the transmission gear ratio, and the engine speed in order to determine if torque reduction is required. The PCM retards the spark as appropriate, in order to reduce the engine torque output if torque reduction is required. The PCM also shuts off the fuel to certain injectors in order to reduce the engine power in the instance of an abusive maneuver.
The following are instances when an engine power reduction is likely to be experienced:
During transmission upshifts and downshifts
During heavy acceleration from a standing start
If the IAC is out of the normal operating range
If the driver is performing harsh or abusive maneuvers, such as shifting into gear at high throttle angles or shifting the transmission from reverse to drive in order to create a rocking motion.
The driver is unlikely to notice the torque management actions in the first 2 instances. The engine power output will be moderate at full throttle in the other 2 instances.
The PCM calculates the amount of spark retard that is necessary to reduce the engine power by the desired amount. The PCM disables the fuel injectors for cylinders 1, 4, 6, and 7 if an abusive maneuver occurs.
PCM Function
The PCM supplies a buffered voltage to various sensors and switches. The PCM controls most components with electronic switches which complete a ground circuit when the switches are turned ON.
PCM Service Precautions
The PCM is designed to withstand the normal current draws that are associated with vehicle operations. Avoid overloading any circuit. When you test for opens or for shorts, do not ground any of the PCM circuits unless you are instructed. When you test for opens or for shorts, do not apply voltage to any of the PCM circuits unless you are instructed. Test these circuits with a digital voltmeter only, while the PCM connectors remain connected.
Aftermarket Add-On Electrical And Vacuum Equipment
Aftermarket electrical and vacuum equipment is defined as any equipment that connects to the vehicle's electrical or vacuum systems that is installed on a vehicle after the vehicle leaves the factory . No allowances in the vehicle design have been made for aftermarket equipment.
Notice
Do not attach add-on vacuum operated equipment to this vehicle. The use of add-on vacuum equipment may result in damage to vehicle components or systems.
Notice
Connect any add-on electrically operated equipment to the vehicle's electrical system at the battery (power and ground) in order to prevent damage to the vehicle.
Even if add-on electrical equipment is installed to strict guidelines, this equipment may still cause the powertrain system to malfunction. Equipment that is not connected to the vehicle's electrical system, such as portable telephones and radios, can also cause a malfunction. The first step in diagnosing any powertrain problem is to eliminate all aftermarket electrical equipment from the vehicle. If the problem still exists, diagnose the problem in the normal manner.
Engine Controls Information
The driveability and emissions information describes the function and operation of the PCM.
The engine controls information contains the following:
The component locations
The wiring diagrams
The PCM terminal end views and the terminal definitions
The Powertrain On-Board Diagnostic (OBD) System Check
The Diagnostic Trouble Code Tables (DTCs)
The component system includes the following items items:
The component and circuit description
The on-vehicle service for each sub-system
The functional checks and the diagnostic tables
The DTCs also contain diagnostic support information containing circuit diagrams, circuit or system information, and helpful diagnostic information.
Maintenance Schedule
06-26-2003, 05:33 AM
#7
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Re: engine problems, need help!!! Check that all the wiring is OK, put CRC or WD-40 into all connectors. Check also TB position, IAT ,MAF, etc. sensor connectors. Check that all the plug wires click and are seated. Check 02 sensor readings and LTRIMs. Check MAF readings. A misfiring cylinder or bad 02 sensor may offset the bank LTRIMs in a way that all cylinders start to have symptoms. After everything is checked it's time to suspect the PCM.
