Virtual Mechanic

PURPOSE
The injectors are designed to inject fuel and when the fuel injector is energised it should spray fuel.  When this happens the combustion chamber will burn it correctly.  Injectors usually run well for 150,000kms then they should be checked or ultrasonically cleaned to be sure that they are not gummed up and are spraying effectively.

THINGS TO LOOK FOR
It is very difficult to check an injector when fitted to the engine.  One of the indications of a faulty injector is that the vehicle is hard to start in the morning.  This may be the fuel injector leaking or the spray pattern may be causing poor economy or poor performance.  These symptoms are usually noticed at around 250,000kms.

IS IT EXPENSIVE TO REPAIR?
Fuel injectors are not cheap at around $30.00-$40.00 each. 

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
Fuel injectors are repairable in that they can be ultrasonically cleaned, spray tested and pressure tested to be sure that they hold the pressure and not leak under pressure.  These tests are performed by a specialist fuel injection service.  It is important to get a before and after report to prove that there was a difference made when the injectors were cleaned.  The fuel injector may also have a fuel injection cleaner poured into the fuel tank.
This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The purpose of the fuel injection solenoid resistors are to lower the voltage going to the fuel injection.

THINGS TO LOOK FOR
The fuel injection solenoid resistors are components that rarely go wrong and are used in the early model EFI units.  They are located in a bank situated on the fire wall but they can be checked individually.

IS IT EXPENSIVE TO REPAIR?
These resistors are expensive and can be replaced from your local spare parts outlet or the wreckers.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The carbon canister is designed to soak the fuel vapours from the fuel tank when the engine is turned off or parked in a hot or cold location.   Over time the fuel may expand and the vapours are soaked up by the carbon canister.  When the engine starts the vacuum will draw the vapours, recycle them, and  prevent the vapours from entering the atmosphere. 

THINGS TO LOOK FOR
The carbon canister may be full of petrol if the fuel tank is full and may start to overflow with petrol.  The carbon canister should be checked at least every 20,000-50,000kms to operate correctly.

IS IT EXPENSIVE TO REPAIR?
The carbon canister is rarely replaced.  If it needs to be replaced, go to your local spare parts outlet or the wreckers.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The fuel pressure regulator is a component that regulates the pressure in the fuel rail and also removes the excess pressure and recycles the fuel back into the fuel tank.  The fuel pressure regulator alternates the pressure on idle and full throttle.  This is a physical component.

THINGS TO LOOK FOR
A fuel pressure regulator should have a vacuum hose connected to it.  If not, this will affect the performance of the fuel pressure regulator.  Also a power loss or a non start may occur due to a faulty fuel pressure regulator.

IS IT EXPENSIVE TO REPAIR?
A fuel pressure regular costs around $80.00-$90.00 and is best fitted by your local mechanic.
TEMPORARY REPAIR AND LONG TERM REPLACEMENT
A fuel pressure regulator can be replaced but it has to be proved that the regulator is faulty and this can be difficult.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The cold start injector time switch and a cold start injector both have one thing in common.  They are designed to operate when the engine is cold.  The cold start time switch is a timer designed to turn the cold start injector on to enrich the fuel mixture for an easy start.

THINGS TO LOOK FOR
The cold start injector time switch and a cold start injector enrichment program may decide to malfunction and not operate at all or it continues to run rich when the engine is warm.  Either way, hard to start or the engine cutting out when it is cold could be an indicator that the program is not operating correctly.  Any engine cutting out when it is cold is a problem and needs to be attended to ASAP.

IS IT EXPENSIVE TO REPAIR?
It is difficult to estimate how much it will cost depending on where the problem is but it does require the attention of a specialised auto electrician.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
If the cold start injector is causing a problem by cutting out and is very difficult to start, try holding the throttle a third of the way and don’t pump it but crank the motor.  Once you start it, get it warm before you drive off.  This is a short term remedy only.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
A coolant temperature sensor is a component designed to feed a value of temperature to the computer.  This allows the computer an accurate measure of temperature making it possible to deliver the correct measure of fuel under each type of temperature.

THINGS TO LOOK FOR
The coolant temperature sensor, if faulty, may affect fuel economy but it is very difficult to check.  A possible check of the fault codes may determine a faulty coolant temperature sensor.  Also removing it and dipping it in water should change the value.  This information will be in your Specific Workshop manual.

IS IT EXPENSIVE TO REPAIR?
Most coolant temperature sensors are around $60.00 depending on the make and model.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
If the price of a new coolant temperature sensor is over the top then you might try the wreckers, but before you fit it, get it tested and keep your receipt just in case.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The purpose of coil and spark plug leads is to deliver high voltage spark from the coil to the spark plugs.  As ignition leads carry a high voltage it is very important to use caution when handling these leads with the ignition on or with the engine idling.  Ignition leads are made of fibres to reduce the possibility of radio wave interference.  Due to the high demand of these leads they may fail at any time. 

THINGS TO LOOK FOR
Ignition leads either deliver high voltage or they start to isolate and end up open circuiting thus creating a misfire.  This shouldn’t be ignored as a misfire may be causing damage to the exhaust system.  Also it may cause damage to the ignition coil as the high voltage can create a carbon track from the secondary lug to the primary lug destroying the coil.  A faulty lead may make the engine difficult to start.  All leads should be tested for resistance. 

IS IT EXPENSIVE TO REPAIR?
Ignition leads should be purchased in a set as they are replaced all at once.  When purchasing leads buy a well-known brand as even new leads can be faulty and testing is required before fitting to make sure that the leads are not faulty. 

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
Testing or fitting any leads must be carried out one at a time as ignition leads are designed to fire in a firing order.  For this reason it is best to remove and replace one lead at a time to prevent messing up the firing order, thus creating a potential backfire.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
Air bags are designed to save lives and reduce the risk of personal injury to the driver and passengers. An extra $3,000.00 to purchase a vehicle fitted with an air bag is well worth the expense. If fitting any additional bumper bar component it may affect the air bag safety operation. 

THINGS TO LOOK FOR
Is it possible to see if an air bag is operating correctly or if buying a second hand vehicle fitted with an air bag?  The only way to check this is to take your vehicle to your mechanic and ask if they can access the fault codes on the air bag and this will show if it’s operating correctly.  Pay for this test procedure and get a receipt, with the fault code number, signed by the mechanic or the technician.  This way you have proof that the air bag is still there and is operating to its specification.

IS IT EXPENSIVE TO REPAIR?
Yes!.  Air bags are expensive. But so is your life!  If your vehicle has been involved in an accident with an air bag going off or when buying a second hand vehicle, make sure it is operating to its design purpose. The average air bag costs around $2,000-$3,000.00.

Mechanical configuration of linkages

 
PURPOSE
A mechanical configuration of linkages is to move the clutch lever fork.  A mechanical configuration is used instead of a hydraulic clutch applicator.  This is also adjustable.  A mechanical configuration may also use a cable that makes it adjustable.  Any clutch assembly must have free play.

THINGS TO LOOK FOR
A mechanical clutch configuration may require adjustment.  If you notice the pedal becoming hard to press this could be an indication of a frayed cable or a clutch assembly sticking.  As the pedal becomes harder to push this shows that it needs to be attended to ASAP.  A mechanical or cable clutch assembly may not tolerate a hard pedal and either snap the clip or rod.  When driving up hill if you notice the engine revs increasing but the speed doesn’t, the clutch assembly is slipping.  It either requires adjustment or the assembly itself needs replacing. 

IS IT EXPENSIVE TO REPAIR?
Most mechanical configurations use a cable assembly which costs between $60.00-$80.00 for the cable.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
A cable or mechanical assembly is best with 2-4mm free play.  A cable without free play will cause the clutch assembly to slip and rapidly deteriorate costing a lot more than the cable or cable adjustment.

 
This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009

PURPOSE
The clutch slave cylinder is designed to plush the clutch lever in order to engage or disengage the clutch lever or fork.  The clutch slave cylinder has a bleeding nipple fitted  and bleeds the clutch hydraulic system.

THINGS TO LOOK FOR
The clutch slave cylinder is a component under pressure while it is in use making it possible to leak.  If there are any drops, or dampness is found around the clutch slave cylinder, it needs to be attended to ASAP.  The most common sign is a clutch pedal going to the floor and also there is difficulty in selecting gears. If you have to force a gear selector into gear this is the time to stop as the selector mechanism is a fragile component that will not tolerate the mechanisms being forced.

IS IT EXPENSIVE TO REPAIR?
The clutch slave cylinder is repairable but not if the bore is scored then it needs to be replaced, costing between $50.00-150.00.

TEMPORARY REPAIR AND LONG TERM REPLACEMENT
It is possible to repair the clutch slave cylinder especially if it is made of cast iron but check the bore.  If the bore is scored it may be better replaced.  The clutch slave cylinder will need to be bled after being installed.

This article is found in the Virtual mechanic CD Rom
You can download it for the price of a latte, but you will learn not to buy a lemon
By Darren Gow-Brown, Melbourne Australia ©2009