The air intake system controls the airflow into the engine and the fuel injector delivers the fuel, so they have to work in harmony to keep your motor running.

If you're an older motorist, you may associate the job of feeding fuel into the engine with the carburettor. However, fuel injectors have been gradually taking over from carburettors since the 1990s. They're simply cleaner and more efficient. How to spot a faulty fuel injector Well shot:The copper sealing washer from the same injector is deformed and eroded on the near side, allowing combustion gas to blow upward over the injector body, and engine oil to leak down into the cylinder.Torque matters: The clamp bolts are stretch bolts, so correct and accurate tightening is critical. When set, they stretch a set amount, but remain elastic. Torque first to 8Nm. In high-pressure diesel systems the injector has to seat into the seal perfectly, otherwise, a pressure bypass can occur, which will reduce the compression in that cylinder and provide very reduced performance, even when a new injector has been installed. (This will often produce degraded combustion). Follow the process: Plug is located in the tip hole to prevent dirt ingress. Then helical brush (inset), spinning in drill, cleans the sides of the injector bores in the head. When fuel injectors are working properly they adjust the amount of fuel being introduced to match the variable airflow. If kept clean and well-maintained, your fuel injectors can also maximise the car's fuel efficiency and minimise pollution.

Second step: After torque tightening, the bolts need a further rotation of 180 degrees. This angle precisely sets the bolt torque, based on thread pitch and calculated stretch. Fit them: Fit each injector (with a new copper washer) into the engine. Locate the clamp over each pair of injectors. This orientates the injectors for spray pattern. Last job: With a hot engine, the software automatically sets and adjusts the injector adaption values over five set points according to engine parameters. ED EVANS SAYS: Injectors tend to be forgotten about until there’s an engine running problem and, of course, not all problems are down to injectors. A multitude of other engine defects can affect the state and lifespan of the injectors, so it’s vital to keep the engine correctly maintained and properly used to avoid replacement of these relatively expensive items. Before thinking about replacing injectors, the engine needs to be inspected by a good specialist to confirm the cause of the symptoms, and the full effects. Other problems include: water in the fuel which can cause the injector nozzles to balloon; carbon can build around the injector nozzles; and combustion gas can blow up past the injector body if the copper seal between the injector and cylinder head fails, exacerbated by the injector clamp bolts stretching.

Injector & Glow Plug Removal

Unplug the power: Next, unplug the injector loom feeds, then lever the plastic covers off from the loom mounts. These also cover the injector clamp fixing bolts. Replaced clips: These are the spill pipe locating clips we found missing on our vehicle. They are brittle, and not easy to buy, so do take care with them. Acontemporary diesel engine relies on high-pressure injector technology, and the Puma engine is no different. This Ford in-line four-pot diesel originated in the Duratorq TDCi for the Ford Transit, but it was used by several other manufacturers, including Land Rover in the Defender from 2007. If your vehicle's engine has started misbehaving in certain ways, it may need replacement fuel injectors. At Halfords, we're one of the UK's leading suppliers of all car parts with an extensive selection available online—and at our 600+ Halfords garages nationwide.

New injectors: Each injector has a unique code on the top. Write each one down, noting which injector is in which cylinder. You’ll need that code for the software, later. Engine abuse:The state of this injector, from a different TDCi Defender, shows why it’s important to maintain the engine in good health. The injector nozzle is coated with carbon and oil, making an efficient fuel spray pattern impossible. This injector hasn’t failed on its own, it’s been destroyed by neglecting other aspects of the engine. Often, such problems can be prevented by cleaning the fuel injectors every 25,000 miles. Specialist products such as Wynn’s fuel injector cleaner are available from Halfords, with different versions for petrol and diesel engines. Where are they?The 2.4 Puma engine bay: like all modern cars, the injectors are hidden under the plastic cover. Two bolts, off it comes, and we can see everything. Seat repair:When the injector seat in the head is contaminated or damaged, it can be cleaned or refaced by inserting a special cleaning or cutting tool down through the injector opening to re-create a flat, sealable face for the new sealing washers.Feed pipes: Remove the four injector feed pipes. Technically, these should be renewed, being part of the high-pressure system. Close inspection shows them to be perfect to reuse. Rough idling with excessive shaking, jerking or vibration when the engine's running but the vehicle isn't moving Are they loose?Remove injector clamp bolts and clamps. These are stretch bolts, so single use. They can stretch further over time, allowing the injector to ‘chatter’ under the clamp. Moment of truth: The injectors should now come out with a good wiggle and some persistence, but they can be very tight if they suffer from carbon build-up or swollen tips. Fuel injectors are also known as injection valves. Comprising a valve and an atomising nozzle, injectors feed fuel into the combustion chamber of each cylinder. That's a vital role, because the engine requires the right combination of fuel and air to function.

On this 120,000-mile 2.4 Defender belonging to Karl Jane, another garage had previously reconditioned and refitted the injectors. But after they were coded to the car, the adaption values were way out, which would ultimately mean the injectors weren’t calibrated accurately at the ECU. Rather than cope with compromised performance, Karl opted to have new units fitted, this time by IRB Developments, where Ian Baughan now shows us the procedure for injector renewal on this 2010 Defender 90. Seals and washers play a crucial role in the correct running of high-pressure systems. For instance; with every new injector kit you will have a soft copper washer - actually, it's a high-pressure seal. It is possible to recondition the injectors, but results can vary, so consider the value of simply replacing old with new. New injectors need to be coded to the car using diagnostic software via the OBD port. There are two things to be aware of when changing injectors. Carbon deposits can form on injector tips, making their extraction from the head difficult. And the mating seat in the head must be free from dirt and deposits when refitting the new injector. Like all of us working on our Land Rovers, consider carefully if you can cope with either issue. If not, then it might be time to take the car to a specialist. There’s no shame in that: wise enthusiasts understand the limits of their abilities. Fuel injectors often start to cause problems when the nozzles get clogged. Symptoms of a faulty fuel injector include: BMW 114D, 116D, 118D, 120D, 216D, 218D, 220D, 316D, 318D, 320D, 420D, 518D, 520D, X1 18D, X1 20D, X2 18 D, X2 20D, X3 18D, X3 20D, X4 20D 2012-Cleanliness within the fuel system is critical so, after removing pipes and components, ensure dirt cannot enter the resulting openings. The injector holes in the head also need to be cleaned to prevent dirt dropping into the engine, as explained in the captions. Code work: Using general diagnostic software, code the injectors to the car. You need to input the four unique codes for the injectors. You did write those down, didn’t you?