This query is asked by my customer for GMC vehicles.
The details are as follows :----
The car will not start?
Car will not crank?
Car has no spark?
How to troubleshoot car battery?
How to test starter solenoid?
http://schematicsdiagram.blogspot.com/2011/06/how-to-test-starter-solenoid.html
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How to test cars starter?
http://schematicsdiagram.blogspot.com/2011/06/how-to-test-cars-starter.html
How to replace starter in car?
car will turn over but will not start?
Car wont start?
Engine will not start?
Car will not start and smells like gas?
The Brake Indicator Light Stays On dash of car?
The ABS and Traction Control Lights stays ON dash of car?
Check Engine Light On car?
How to replace Interior Lights on car?
Car lights not working, even after replacing the bulb/lamp?
How to replace head lights on car?
How to replace Parking, turn, and Brake Lights on car?
How to replace power window motor in car?
How to test relays on car?
How to troubleshoot Engine Misfires?
The spark plug firing order for car?
Where is the Thermostat located in car?
How to recharge AC on Auto/Truck/car?
Car Stereo says PROTECT or turns OFF?
How to Replace Coil Springs?
How to Replace a Rear Lift Gate Locking Mechanism?
How to Clean a Fuel System
How to Replace a Windshield
How to Replace a Mass Air Flow Sensor
How to Replace a Rear Distance Sensor
How to Replace a Muffler
How to Replace an Engine
How to Replace an Intake Manifold Gasket
How to Replace an Oil Pump
How to Replace a Windshield Wiper Motor
How to Replace a Distributor Cap
How to Replace a Door Weather Stripping
How to Replace a Freeze Plug
How to Replace a Head Gasket
How to Replace a Heater Core
How to Replace Spark Plugs?
How to Replace a Front Bumper Cover
How to Replace a Manual Transmission
How to Replace a Headlight Bulb
How to Replace a Headlight Switch
How to Replace Windshield Wiper Blades
How to Replace a Cooling Fan
How to Replace a Catalytic Converter
How to Replace an Engine Mount
How to Replace a Fog Light Assembly
How to Change Engine Oil and Filter
How to Replace a Power Seat Switch
How to Replace a Rear Main Seal
How to Repair a Defroster Grid
How to Replace an AWD Transfer Case
How to Replace a Power Seat Motor
How to Replace Power Steering Fluid
How to Replace a Power Window Switch
How to Pressure Test a Radiator and Cap
How to Replace a Radiator
How to Replace an Energy Absorber
How to Replace Heater Core Hoses
How to Replace Wheel Lug Nuts
How to Replace a Tire Valve Stem
How to Change a Flat Tire
How to Replace Leaf Springs
How to Replace a Heater Control Valve
How to Replace Transmission Cooler Lines
How to Replace an Ignition Control Unit
How to Replace a Brake Hose
How to Replace a Transfer Case Rear Output Seal
How to Replace a Seat Belt and Seatbelt Retractor
How to Replace a Power Steering Rack
How to Bleed Brakes with a Tool
How to Replace a Tail Light Bulb
How to Check Automatic Transmission Fluid Level
How to Change Automatic Transmission Fluid and Filter
How to Replace Vacuum Hoses
How to Replace an Air Intake Boot
How to Replace a Valve Cover Gasket
How to Replace a Water Pump
How to Replace a Windshield Wiper Switch
How to Replace Window Run Channel Seals
How to Replace a Window Regulator
How to Balance a Tire and Wheel
How to Replace a Radiator Support
How to Replace
How to Replace a Proportioning Valve
How to Replace an Upper Radiator Hose
How to Replace a Lower Radiator Hose
How to Check for Loose or Worn Suspension
How to Replace an Oil Pressure Switch (Sensor)
How to Replace a Fender Liner or Splash Shield
How to Replace a Hood Insulator
How to Repair a Hood Hinge
How to Replace a Brake Pedal Return Spring
How to Replace a Transfer Case Front Output Seal
How to Replace a Hood Latch/Lock Assembly
How to Replace Mud Flaps (Mud Guards)
How to Replace a Transfer Case Shift Linkage
How to Replace a Transmission Mount
How to Replace a U-Joint
How to Replace a Washer Tank
How to Replace an A/C Line or Hose
How to Replace a Heater and A/C Blower Motor
How to Replace an ABS Control Unit
How to Perform a Brake Adjustment
How to Replace an Alternator Belt
How to Replace an Emblem
How to Replace an Exhaust Manifold Gasket
How to Replace a Tail Pipe
How to Replace Shock Absorbers
How to Replace a Strut Assembly
How to Replace a Driveshaft
How to Replace a Wheel Cylinder
How to Replace a Hood
How to Replace a Brake Disc (Rotor)
How to Replace a Metal License Plate Bracket
How to Replace a Power Steering Pump
How to Perform a Basic Engine Tune Up-Oil Change
How to Replace a Distributor Cap and Rotor ?
How to Repair a Valance
How to Replace a Turn Signal Switch
How to Replace a Plastic Bumper Cover
How to Replace a Parking Brake Cable
How to Replace Windshield Wiper Blade Refills
How to Replace a Corner Light
How to Replace a Bumper Bracket or Side Support
How to Replace a Grille
How to Replace a Locking Hub
How to Replace a Fender
How to Replace a Power Steering Hose
How to Replace a Tailgate
How to Replace a Soft Top
How to Replace a Carburetor
How to Replace a Bumper Trim
How to Replace Trunk Strut
How to Replace a Front End Cover
How to Replace a Front Pipe
How to Replace an Antenna Mast
How to Replace a Side Marker Light Assembly
How to Replace a Spoiler
How to Replace a Door Lock
How to Replace a Throttle Body
How to Replace a Throttle Position Sensor
How to Replace a Grille Insert
How to Replace a Fan Shroud Assembly
How to Replace an Engine Splash Shield
How to Replace a Turn Signal Light Assembly
How to Replace a Headlight Assembly
How to Replace a Park Light Assembly
How to Replace an Expansion Tank
How to Replace an Exhaust System
How to Replace a Fender Trim
How to Replace a Headlight Door
How to Replace a Fan Shroud
How to Replace a Harmonic Balancer
How to Replace a Header Panel
How to Replace a Fuel Tank
How to Replace a Fuel Tank Cap
How to Replace a Distributor
How to Replace an EGR Valve
How to Replace an Oxygen Sensor
How to Replace an Ignition Wire Set
How to Replace a Tail Light
How to Replace a Door Handle
How to Replace a Hood Strut
How to Replace Tail Light Assembly
How to Replace a Front Bumper
How to Replace a Fuel Pump Assembly
How to Replace an Axle Assembly
How to Replace a Tailgate Handle
How to Replace a Wheel Hub Assembly
How to Replace a Control Arm
How to Replace a Window Regulator with Motor
How to Replace a Headlight
How to Check the Brake Fluid Level
How to Replace a Parking Brake Switch
How to Replace a Blower Motor Resistor
Horn stopped working?
How to change the outer door weather strip?
Car slows down when it gets hotter?
Warning lights on and speedometer died?
Car won't rev past 1900 rpms?
How to Disable Theft Security on Car?
http://howtobyme.blogspot.com/2011/11/how-to-disable-theft-security-on-car.html
The details are as follows :----
See Figures 1, 2 and 3
The Central Multi-port Fuel Injection (CMFI) system, found on 1994-95 4.3L models, functions similarly to the TBI system in that an injection assembly (CMFI unit) is centrally mounted on the engine intake manifold. The major differences come in the incorporation of a split (upper and lower) intake manifold assembly with a variable tuned plenum (using an intake manifold tuning valve) and the CMFI unit's single fuel injector which feeds 6 poppet valves (1 for each individual cylinder).
The non-repairable CMFI assembly or injection unit consists of a fuel meter body, gasket seal, fuel pressure regulator, fuel injector and six poppet nozzles with fuel tubes. The assembly is housed in the lower intake manifold. Should a failure occur in the CMFI assembly, the entire component must be replaced as a unit.
As with other fuel injection systems, all injection and ignition functions are controlled by the computer control module. The module accepts inputs from various sensors and switches, calculates the optimum air/fuel mixture and operates the various output devices to provide peak performance within specific emissions limits. The module will attempt to maintain the ideal air/fuel mixture of 14.7:1 in order to optimize catalytic converter operation. If a system failure occurs that is not serious enough to stop the engine, the module will illuminate the SERVICE ENGINE SOON light and will continue to operate the engine, although it may need to operate in a backup or fail-safe mode.
Fuel is supplied to the injector through an electric fuel pump assembly which is mounted in the vehicle's fuel tank. The module provides a signal to operate the fuel pump though the fuel pump relay and oil pressure switch. The CMFI unit internal pressure regulator maintains a system pressure of approximately 58-64 psi (400-440 kPa). When the injector is energized by the control module, an armature lifts allowing pressurized fuel to travel down the 6 fuel tubes to the poppet valves. In the poppet valves, fuel pressure (working against the extension spring force) will cause the nozzle ball to open from its seat and fuel will flow from the nozzle. It takes approximately 51 psi (350 kPa) to force fuel from the poppet nozzle. Once the module de-energizes the injector, the armature will close, allowing fuel pressure in the tubes to drop and the spring force will close off fuel flow.
Other system components include a pressure regulator, an Idle Air Control (IAC) valve, a Throttle Position (TP) sensor, Intake Air Temperature (IAT) sensor, Engine Coolant Temperature (ECT) sensor, a Manifold Absolute Pressure (MAP) sensor and an oxygen sensor.
The idle air control valve is a stepper motor that controls the amount of air allowed to bypass the throttle plate. With this valve the computer control module can closely control idle speed even when the engine is cold or when there is a high engine load at idle.
The computer module used on CMFI vehicles has a learning capability which is used to provide corrections for a particular engine's condition. If the battery is disconnected to clear diagnostic codes, or for safety during a repair, the learning process must start all over again. A change may be noted in vehicle performance. In order to "teach'' the vehicle, make sure the vehicle is at normal operating temperature, then drive at part throttle, under moderate acceleration and idle conditions, until normal performance returns.
This will help.
Thanks.
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See below more solved car problems :--------
This are the sections, you can go through and click the link to read its troubleshooting.
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The car will not start?
-----------------
Car will not crank?
-----------
Car has no spark?
-------------
How to troubleshoot car battery?
-----------------
How to test starter solenoid?
http://schematicsdiagram.blogspot.com/2011/06/how-to-test-starter-solenoid.html
--------------------
How to test cars starter?
http://schematicsdiagram.blogspot.com/2011/06/how-to-test-cars-starter.html
How to replace starter in car?
-----------
car will turn over but will not start?
-----------------
Car wont start?
Engine will not start?
----------
Car will not start and smells like gas?
The Brake Indicator Light Stays On dash of car?
The ABS and Traction Control Lights stays ON dash of car?
Check Engine Light On car?
-------------------------
How to replace Interior Lights on car?
Car lights not working, even after replacing the bulb/lamp?
Click this link below:--
---------------
How to replace head lights on car?
--------------------
How to replace Parking, turn, and Brake Lights on car?
How to remove the door panel on car?
How to replace power window motor in car?
How to test relays on car?
-----------------------------
How to troubleshoot Engine Misfires?
------------
The spark plug firing order for car?
------------------------
Where is the Thermostat located in car?
How to recharge AC on Auto/Truck/car?
-------------------
How to trouble shoot speedometer?
Car Stereo says PROTECT or turns OFF?
How to Replace Coil Springs?
How to Replace an Oil Pan Gasket?
How to Replace a Fuel Injector
How to Replace a C.O.P. Type Ignition Coil?
How to Replace a Fuel Pressure Regulator?
How to Replace a Fuel Pump?
How to Replace a Rear Lift Gate Locking Mechanism?
How to Clean a Fuel System
How to Replace an Ignition Coil
How to Replace a Windshield
How to Replace a Mass Air Flow Sensor
How to Replace a Rear Distance Sensor
How to Replace a Muffler
How to Replace an Engine
How to Replace an Intake Manifold Gasket
How to Replace an Oil Pump
How to Lubricate a Brake Pedal Linkage ?
How to Replace a Windshield Wiper Motor
How to Replace a Distributor Cap
How to Replace a Door Weather Stripping
How to Replace a Freeze Plug
How to Replace a Head Gasket
How to Replace a Heater Core
How to Replace Spark Plugs?
How to Replace a Rear Axle Bearing?
How to Replace a Front Bumper Cover
How to Replace a Manual Transmission
How to Replace a Headlight Bulb
How to Replace a Headlight Switch
How to Replace Windshield Wiper Blades
How to Replace a Cooling Fan
How to Replace a Catalytic Converter
How to Replace an Engine Mount
How to Replace a Fog Light Assembly
How to Change Engine Oil and Filter
How to Replace a Power Seat Switch
How to Replace a Rear Main Seal
How to Repair a Defroster Grid
How to Replace an AWD Transfer Case
How to Replace a Plastic License Plate Bracket?
How to Replace a Power Seat Motor
How to Replace Power Steering Fluid
How to Replace a Power Window Switch
How to Replace a Quarter Glass Panel?
How to Pressure Test a Radiator and Cap
How to Replace a Radiator
How to Repair a Hood.
How to Replace an Energy Absorber
How to Replace Heater Core Hoses
How to Replace a Thermostat.
How to Rotate Tires.
How to Replace Wheel Lug Nuts
How to Replace a Tire Valve Stem
How to Change a Flat Tire
How to Replace Leaf Springs
How to Replace a Heater Control Valve
How to Replace Transmission Cooler Lines
How to Replace an Ignition Control Unit
How to Replace a Brake Hose
How to Replace a Transfer Case Rear Output Seal
How to Replace a Seat Belt and Seatbelt Retractor
How to Replace a Power Steering Rack
How to Bleed Brakes with a Tool
How to Replace a Tail Light Bulb
How to Check Automatic Transmission Fluid Level
How to Change Automatic Transmission Fluid and Filter
How to Replace Vacuum Hoses
How to Replace an Air Intake Boot
How to Replace a Valve Cover Gasket
How to Replace a Water Pump
How to Replace a Windshield Wiper Switch
How to Replace Window Run Channel Seals
How to Replace a Window Regulator
How to Balance a Tire and Wheel
How to Replace a Window Motor
How to Adjust a Hood Release Latch?
How to Replace a Radiator Support
How to Replace a Rear Pinion Seal.
How to Replace Battery Cables
How to Replace a Proportioning Valve
How to Replace an Upper Radiator Hose
How to Replace a Lower Radiator Hose
How to Replace a Timing Belt?
How to Check for Loose or Worn Suspension
How to Check for Loose Steering System
How to Replace an Oil Pressure Switch (Sensor)
How to Replace a Fender Liner or Splash Shield
How to Replace a Hood Insulator
How to Replace a Rear Differential.
How to Repair a Hood Hinge
How to Replace a Brake Pedal Return Spring
How to Replace a Door Shell.
How to Replace a Transfer Case Front Output Seal
How to Replace a Hood Latch/Lock Assembly
How to Replace a Lift Gate Strut
How to Replace Mud Flaps (Mud Guards)
How to Check Differential Oil Leaks and Replace Oil.
How to Replace a Mirror
How to Replace a Transfer Case Shift Linkage
How to Replace a Transmission Mount
How to Replace a U-Joint
How to Replace a Washer Tank
How to Replace an A/C Line or Hose
How to Replace a Heater and A/C Blower Motor
How to Replace an ABS Control Unit
How to Perform a Brake Adjustment
How to Replace an Alternator Belt
How to Replace an Emblem
How to Replace an Exhaust Manifold Gasket
How to Replace a Tail Pipe
How to Replace Shock Absorbers
How to Replace a Strut Assembly
How to Replace a Driveshaft
How to Replace a Wheel Cylinder
How to Replace a Hood
How to Replace a Brake Disc (Rotor)
How to Replace a Metal License Plate Bracket
How to Replace a Power Steering Pump
How to Perform a Basic Engine Tune-Up
How to Perform a Basic Engine Tune Up-Oil Change
How to Perform a Basic Engine Tune Up-Spark Plug and Wire Change
How to Replace a Distributor Cap and Rotor ?
How to Repair a Valance
How to Replace a Turn Signal Switch
How to Replace a Plastic Bumper Cover
How to Replace a Parking Brake Cable
How to Replace Windshield Wiper Blade Refills
How to Replace a Corner Light
How to Replace a Bumper Bracket or Side Support
How to Replace a Washer Pump.
How to Replace a Grille
How to Replace a Locking Hub
How to Replace a Fender
How to Replace a Power Steering Hose
How to Replace a Tailgate
How to Replace a Soft Top
How to Replace a Carburetor
How to Replace a Bumper Trim
How to Replace Trunk Strut
How to Replace a Front End Cover
How to Replace a Front Pipe
How to Replace an Antenna Mast
How to Replace a Side Marker Light Assembly
How to Install a Carpet on car?
How to Replace a Spoiler
How to Replace a Mirror Glass on car?
How to Replace a Step Bumper?
How to Replace a Door Lock
How to Replace a Throttle Body
How to Replace a Throttle Position Sensor
How to Replace a Grille Insert
How to Replace a Fan Shroud Assembly
How to Replace an Engine Splash Shield
How to Replace a Turn Signal Light Assembly
How to Replace a Headlight Assembly
How to Replace a Park Light Assembly
How to Replace an Expansion Tank
How to Replace an Exhaust System
How to Replace a Fender Trim
How to Replace a Headlight Door
How to Replace a Fan Shroud
How to Replace a Harmonic Balancer
How to Replace a Header Panel
How to Replace a Fuel Tank
How to Replace a Fuel Tank Cap
How to Replace a Distributor
How to Replace an EGR Valve
How to Replace an Oxygen Sensor
How to Replace an Ignition Wire Set
How to Replace a Tail Light
How to Replace a Door Handle
How to Replace a Hood Strut
How to Replace Tail Light Assembly
How to Replace a Front Bumper
How to Replace a Fuel Pump Assembly
How to Replace an Axle Assembly
How to Replace a Tailgate Handle
How to Replace a Wheel Hub Assembly
How to Replace a Control Arm
How to Replace a Window Regulator with Motor
How to Replace a Headlight
How to Check the Brake Fluid Level
How to Replace a Parking Brake Switch
How to Replace a Blower Motor Resistor
How to replace frost plug on car?
Horn stopped working?
How to clean egr valve on Isuzu Amigo?
Cruise control stopped working?
Car is stuck in park and the shift will not move?