Broad terms can sometimes be confusing for a number of procedures.

Tune relates to maintenance: In simple terms, a series of maintenance procedures, which will have a large effect on economy and performance and prevent higher than normal combustion temperatures, or over fueling and carbon build up and oil degradation, resulting in engine failure.

Diagnosis is used when a vehicle is presented with a particular problem needing correction to run “normal”

When Should We Do A Tune, And What Is It?

Unlike the oil change/filter type maintenance service performed on a more regular basis, we need to perform the engine “tune” on a less frequent but just as important basis, and we need to find a routine that suits the individual car and driver and once again the environment the vehicle operates under has a huge influence over this.

Set tune schedule for all vehicles these days seems to be an all most impossible reality to come up with. Advice on your type of vehicle and the mileage you are doing with reference to the amount of cold short distance driving, needs to be considered when deciding when certain procedures would advantage you.

Work out what you need maintained. Each type of car will have a number of variables such as the style and type of spark plug from single or double electrode to platinum tip electrode varying life from 30,000 to 100,000 km.

Fuel filters on older carburettored vehicles only cost about $3.00 and have a life expectancy of 20,000 km, some late model E.F.I. fuel filters are scheduled to be replaced at 100,000 km however are part of the fuel pump assembly which are in the fuel tank requiring 2-4 hrs labour plus the cost of the fuel pump assembly as a normal maintenance item, this must be factored in as what is called a tune in this instance which an end result for this vehicle may be a total bill of some $600-$700 just for what you might call a tune.

One of the most neglected areas with some of the best results for economy and performance is the inlet manifold throttle body and injector area, this is the fuel delivery area, newer high octane “clean” fuels and fuel system cleaners will help keep these areas cleaner, but a proper injector clean and service/test will be needed from time to time, with the general trend for us to be doing less driving over shorter distances we can’t avoid cold engine temperature carbon build up.

Unfortunately the less we drive, the more our cars will suffer, the more they need maintaining.

Remember, a rolling stone gathers no moss, its pretty true inside your engine, the less mileage, the more moss/carbon will gather, the less open freeway driving you do the more prone you are to needing oil changes, and needing injector and throttle body cleans to get the best out of the tank of expensive fuel you have put in. An average driver, that’s one considered to do 20,000 kl/year should have an injector service as a maintenance item without seeing a huge benefit about every 30,000 km, however cost is high and maybe this could be stretched to 40-50,000, most cars in reality are 60-70,000 before this area is properly addressed and most see a major improvement, usually oxygen sensors are also replaced at around the 60-100,000 as being their life expectancy, with good results.

Cars doing less than 10-15,000 km/year are usually the short distance cars who are prone to not warming up creating higher amounts of carbon fouling injectors, throttle bodies and intakes much faster and will see benefits from fuel system services from as early as 20,000 km. So, we now have to start looking at the bowser nudging $1.20 litre, what I have been saying in the last paragraph is what we have been doing, up to now with the price of fuel its been reasonable, but, to run economically we now need to keep our cars in peak tune. This means where we stretched out injector cleans to 70,000 km or more, not spending $150.00-$300.00 on an injector service probably cost us $500.00 over 3 years in extra fuel, not spending $30.00 extra for synthetic oil (low friction fuel saving oil) and doing an extra oil change in between normal servicing probably cost you another $100.00. Think about it.


If you have a specific problem, misfire, cutting out, lacks power, this is not a tune, and it needs to be diagnosed. With late model vehicles, we need to use diagnosis equipment such as vehicle specific computer scan tools and engine analysers to extract on board stored information that the vehicles computer may have stored to tell us what EFI device may have failed in operation.

It is time consuming and open ended, prices for each procedure for maintenance can be established and estimated before work commenced, undiagnosed faults are an unknown and cannot be quoted that easily. The engine management system of a late model vehicle is a complex piece of engineering containing a number of controlling electronic switches, solenoids and motors, fuel pumps, fuel injectors, and sensors, all controlled by the computer, to maintain timing, spark, and fuel flow, at its most efficient and peak power range. Each component has specific operating requirements, and may operate under given specifications such as voltage and resistance. When diagnosing component failure, indications such as fault codes in the computer, or certain fault characteristics may take us to one or a number of components that would cause the fault, on an older vehicle a number of components may show as being out of range/specification yet the vehicle will still operate. If one component has failed completely, possibly lets say open circuit, it is logical that this component needs replacement, however, the failure of this component may be because of a continued operation of another component operating outside its normal range causing load and resultant failure of that component, so costs escalate, requiring the replacement of a number of components to bring the system back to its desired specification. Intermittent faults can cause lengthy diagnosis, in some cases, because the issue is not presenting itself at time of repair, we can test each item suspected only to find everything operating within specification, diagnosis then becomes little more than guesswork, to resolve your vehicle possibly cutting out in traffic, usually out of business hours, possibly in dangerous positions in traffic, we need to commit expensive components to your vehicle, once fitted it cannot be returned and may not be the cause of the failure, however we have to start somewhere. At Apps Automotive, we have committed to the frontline of tune and fault diagnosis, we have made ongoing investments in diagnostic scanners, engine analysers, injection cleaning equipment, and staff training to be able to offer diagnostic capabilities to equal or exceed our competitors in the motor trade industry. Although at some stages, diagnosis may seem to lead us to expensive component replacement that may initially seem unnecessary, we assure you, this needs to be done and it will be the same procedure taken by anyone committing to resolve the fault in your vehicle.