Can do this properly at home, or do I need to take to someone with an ultrasound cleaning bath?

Do they need cleaning? What symptoms? Professionals do a spray pattern test before and after cleaning, as well as a leak test. Worth getting it done, but only if you are sure it needs doing. I own 2 cars, 10 injectors with more than 200,000 km on each of them, and I don't feel the need to pull them out and get them cleaned.

eh just run a few tanks of 98 ron

IF you want them cleaned you have 2 options

You can go onboard cleaning, this is done with an extremely volotile solution that will not only clean the injectors but also clean the backs of the valves and the tops of the pistons, is extremely effective however you can not do spray tests

Second option is to do ultrasonic, it is far better in so far as getting clean injectors however you do not get the benefit of the top end clean

Bottles, as discussed here on these forums many a time as well as "98 Ron" will not clean your injectors

IF you want them cleaned you have 2 options

You can go onboard cleaning, this is done with an extremely volotile solution that will not only clean the injectors but also clean the backs of the valves and the tops of the pistons, is extremely effective however you can not do spray tests

Second option is to do ultrasonic, it is far better in so far as getting clean injectors however you do not get the benefit of the top end clean

Bottles, as discussed here on these forums many a time as well as "98 Ron" will not clean your injectors

Hey would you know what that solution is called? is it available at the shops?

There was a very good product from Castrol, forgot the name ATM but i bought a few years back after reading many articles on it and discussed it with my Castrol rep. It cleans the whole fuel system and even gets the gunk outte the exhaust system. I'll try and find the bottle.
I used it in my old Prem, worked VERY well.

Dumb question here - what are the symptoms of injectors in need of a clean? I would have thought they would stay clean, with all that hydrocarbon liquid being pumped through them, unless you are burning oil and the intake valves leak and allow blowback. Do the solenoids/actuators ever give any trouble? Can they be checked with a multimeter?

Found my old bottle. It's called "Fuel Doctor".

Answering my own question:

So why do we need to clean injectors? Injectors become clogged with fuel residues (something similar to varnish) due to the evaporation of fuel in the injector nozzle when the engine has been stopped. Every time you stop a hot engine a small amount of residue adds to the already present build up. The more frequent the stops, the more rapidly the build up accumulates. This accumulation eventually reduces the flow of fuel through the injector and disrupts its spray pattern, causing the engine to run lean. This can manifest itself in a number of ways, although the most common is driveability problems such as flat spots and hesitations.

Most, if not all, fuels contain detergents to clean the fuel system and injectors, with premium fuels often containing higher concentrations. However there is a limit to what they can achieve and it is sometimes necessary to use a more severe cleaner to remove long-term accumulations.

There are a number of common methods for cleaning injectors, the most basic of which is the DIY in-tank additive. Like many additives, the content of fuel system treatments is a mystery to those not in the industry. While some fuel manufacturers produce their own fuel system cleaners that they openly promote as being a more concentrated form of the cleaning package used in their fuels, the make-up of the majority of products is not widely known. Nor in many cases is their effectiveness.

While in tank cleaners may offer some benefits, they have a couple of drawbacks. Firstly their strength, and therefore their ability to remove heavy deposits, is limited by the fact that some fuel system components may be damaged by very aggressive cleaners. Secondly, the effectiveness of the process is unknown, as apart from removing and testing, there is no way of checking the injector's flow rate and spray pattern - two of the critical aspects of an injectors operation. In fact sometimes the only measure will be that you think the car goes better.

The second form of injector cleaning falls under the general heading of Rail Flush Kits. In these systems the fuel pump is disabled. The fuel lines are then removed and replaced with a system that delivers a concentrated cleaner directly to the fuel rail and injectors. The engine is then run until the cleaning agent is used up. This system has the advantage that a more aggressive cleaner can be used, however like in-tank cleaners, the outcome may still be uncertain.

The most certain and effective cleaning method is to remove the injectors from the vehicle for cleaning in a specialist injector cleaner. Such specialised cleaning equipment often utilises ultra-sonic cleaning in addition to special cleaning chemicals. Such systems also have the advantage of being able to test the injector's flow rate and spray pattern before and after cleaning to determine the effectiveness of the procedure and the serviceability of the injectors. The disadvantage of such systems is the added labour costs involved in removing and refitting the injectors.

Blocked injectors are not the only cause of drivability problems. An increasingly common problem with later vehicles is the build up of organic material in the throttle body and intake manifold, and carbon on intake valves and ports - all of which can cause a range of problems that can be difficult to trace. Generally these problems are dealt with by spraying the affected areas with a quite aggressive cleaner to soften and dissolve the build up.
How often should injectors be cleaned?

There really is no definite time to clean injectors as it will very much depend on how the car gets used and whether it is a model that is sensitive to the problem. If it is a car that develops unexplained flat spots or hesitations it may be worth investigating for throttle body build up as well.

Found my old bottle. It's called "Fuel Doctor".

Thanks for that

Answering my own question:

So why do we need to clean injectors? Injectors become clogged with fuel residues (something similar to varnish) due to the evaporation of fuel in the injector nozzle when the engine has been stopped. Every time you stop a hot engine a small amount of residue adds to the already present build up. The more frequent the stops, the more rapidly the build up accumulates. This accumulation eventually reduces the flow of fuel through the injector and disrupts its spray pattern, causing the engine to run lean. This can manifest itself in a number of ways, although the most common is driveability problems such as flat spots and hesitations.

Most, if not all, fuels contain detergents to clean the fuel system and injectors, with premium fuels often containing higher concentrations. However there is a limit to what they can achieve and it is sometimes necessary to use a more severe cleaner to remove long-term accumulations.

There are a number of common methods for cleaning injectors, the most basic of which is the DIY in-tank additive. Like many additives, the content of fuel system treatments is a mystery to those not in the industry. While some fuel manufacturers produce their own fuel system cleaners that they openly promote as being a more concentrated form of the cleaning package used in their fuels, the make-up of the majority of products is not widely known. Nor in many cases is their effectiveness.

While in tank cleaners may offer some benefits, they have a couple of drawbacks. Firstly their strength, and therefore their ability to remove heavy deposits, is limited by the fact that some fuel system components may be damaged by very aggressive cleaners. Secondly, the effectiveness of the process is unknown, as apart from removing and testing, there is no way of checking the injector's flow rate and spray pattern - two of the critical aspects of an injectors operation. In fact sometimes the only measure will be that you think the car goes better.

The second form of injector cleaning falls under the general heading of Rail Flush Kits. In these systems the fuel pump is disabled. The fuel lines are then removed and replaced with a system that delivers a concentrated cleaner directly to the fuel rail and injectors. The engine is then run until the cleaning agent is used up. This system has the advantage that a more aggressive cleaner can be used, however like in-tank cleaners, the outcome may still be uncertain.

The most certain and effective cleaning method is to remove the injectors from the vehicle for cleaning in a specialist injector cleaner. Such specialised cleaning equipment often utilises ultra-sonic cleaning in addition to special cleaning chemicals. Such systems also have the advantage of being able to test the injector's flow rate and spray pattern before and after cleaning to determine the effectiveness of the procedure and the serviceability of the injectors. The disadvantage of such systems is the added labour costs involved in removing and refitting the injectors.

Blocked injectors are not the only cause of drivability problems. An increasingly common problem with later vehicles is the build up of organic material in the throttle body and intake manifold, and carbon on intake valves and ports - all of which can cause a range of problems that can be difficult to trace. Generally these problems are dealt with by spraying the affected areas with a quite aggressive cleaner to soften and dissolve the build up.
How often should injectors be cleaned?

There really is no definite time to clean injectors as it will very much depend on how the car gets used and whether it is a model that is sensitive to the problem. If it is a car that develops unexplained flat spots or hesitations it may be worth investigating for throttle body build up as well.

nice http://www.racq.com.au/motoring_advice/about_your_car/car_factsheets/injector_cleaning

Yep - I should have put the link in. Lazy. I wasn't trying to claim it as my own work.