I'm starting a thread for people to read when they think there fuel useage is too high, i know it comes up alot. If people can think of possible reasons as to why it may be high, how to check, how to resolve, it would be most appreciated if you would write it here so i can add it and we can get a doco/sticky started

//If your experiencing high fuel economy 14Litres per hundred kilometers plus, there are quite a few areas that may be the cause or part of:

-Vacuum leak(s):

-Spark plugs: They wear, the gaps enlarge and need to be regapped.

-Fuel pump: Not usually in need of replacement unless you've run on lpg with low petrol in your tank.
Remember your fuel pump runs at 40,000rpm and is not self lubricating, it is lubricated and cooled by the petrol flowing through it, and continues to run while you are on gas, but instead of the petrol entering the engine, the injectors are cut off and returns to your fuel tank via the petrol return line.

-Fuel filter: Over time these do get 'clogged' from particles in your fuel.

-Fuel pressure: See Gregories Guide service manual for fuse to remove whilst car is running, wait for the car to stall, fit the fuse, turn key to 'acc' a few times to 'prime' the fuel lines. Start amd enjoy lower fuel pressure = better economy.

-Faulty Catalytic converter: part of the emissions control in cars, in older cars the internals have been known to 'collapse', causing a rather large restriction on the exhaust side of the engine, a replacement catalytic converter will solve the problem.

-Injectors (if on petroleum): If an injector is 'clogged' it will not atomise the fuel it is squirting into the cylinder chamber, these can be serviced at mechanics advertising the service in the yellow/white pages.

-Driving style: Are you heavy footed?

-Oxygen sensor: These are located below the extractors on the exhaust, over time these do fail and require replacement. For around $80 you can get a new bosch replacement and fit it yourself quite easily. You can test them with a multimeter before replacing them, instructions are in the Gregories Guide.


If anyone has any ideas or suggestions please fire away, remember this is to help users and we are all here to learn and have a good time.

If anyone wants to add, modify or elaborate on, please do

Intake gasket

vac leak - check around the brake booster, large line to booster, vac tree it connects to, map hose & sensor, small hose to fuel reg & reg, line to BBM servo