Jaguar S Type V6 2.5L Petrol
LV02S Task 4 Remove and refit spark
plugs and fuel injectors.
Included in this task also:
Removing inspecting and refitting the
Removing, inspecting and refitting the
ignition coil packs & spark plugs
You will need to wear gloves and goggles whilst completing this task to protect your skin and eyes from fuel
residue. You will also need a hand lamp to avoid straining your eyes whilst you are working.
You will need to prepare the equipment shown below to complete this task.
Lamp, 2 x Hose clamps, Small flat blade screwdriver, Medium posidrive screwdriver
3/8 drive, ratchet, Long extension, spark plug socket
1/4 drive, ratchet, 8mm shallow socket, 10 mm shallow socket, 10mm deep socket, universal joint, medium and
Hose clip removal tool, long nosed pliers
It is very important that you remove the fuel pump relay from the relay plate in the boot of the vehicle. This is
to prevent accidental activation of the fuel pump whilst the task is in progress.
You will need to fit vehicle protection (VPE) to protect the vehicle from scratches, dirt and oil during this task.
You should fit, wing covers, floor mats and a steering wheel cover. Always carry out a pre-work check, this
should include checking the exterior for damage and recording any found onto your job-card.
The intake manifold is shown in this picture to the left, the engine cover is on the right and the air cleaner and
throttle body are at the very front. You will need to remove the air intake it has 2 x jubilee clips.
Once you have removed the intake pipe you will be left with the remainder of the air cleaner assembly and an
electrical connector onto the air mass meter, to remove the electrical connector be sure to release the securing
clip by pushing inwards, ask your lecturer for help if required. Then release the two clips to the right and lift
the top off the air cleaner.
You should now be able to remove the engine cover, you will have to take off the oil filler cap and release the
four clips shown by turning anticlockwise ¼ of a turn with a posidrive screwdriver.
The next job is to remove the two intake manifold pre-heater hoses, be careful as these will contain some
coolant residue. Use the hose clip removal tool to undo each of the two hose clips. As you can see in the
picture you will need to use clamps on each of the hoses to prevent lots of coolant from leaking out.
Now disconnect the two electrical plugs from the throttle position switch and the throttle housing. You will
need to push the plastic tag in with your thumbnail whilst pushing the connector on to release it.
Now you will need to disconnect the EVAP canister pipe by pushing in the two clips either side and gently
pulling apart the connector.
Now undo and remove the two 8mm nuts securing the engine cover mounting bracket and move it aside.
There is no need to cut off the cable tie it can stay in position.
This pipe connects the fuel feed from the pump and fuel tank to the fuel injector rail it will already be
disconnected for you because a specialist tool is required to release it. There is a 10mm bolt holding the metal
pipe to the cylinder head which will need removing and you will also need to remove the electrical plug from
the fuel pressure sensor. Note that there is a Schrader type valve where a fuel pressure gauge can be fitted.
This is a tricky step which involves working down the back of the O/S cylinder head. You need to disconnect the MAP
sensor and IMT valves which have an electrical connector each 3 in total. There is also a vacuum connector for the
brake vacuum servo which will need to be disconnected. Be very careful that you don’t pull too hard on the pipe, you
will not need any tools, just push the collar around the pipe inwards with your finger nails and gently pull it clear. There
is also another vacuum hose which just simply pulls off.
Remove the bolts holding the inlet manifold bracket to the O/S cylinder head 1 x 10mm there is also 1 x 8mm
to remove towards the rear of the manifold by the engine cover mounting bracket.
Remove 6 x 8 mm bolts holding the inlet manifold to the cylinder head and lift it clear. You will need to insert
paper towel into the exposed intake holes to prevent any debris falling inside the engine. You can now see the
exposed fuel injection rail, fuel injectors and ignition coil packs.
There is a safety bracket fitted around the rear of the fuel rail over the pressure sensor to protect it from
snapping off and leaking fuel in the event of an impact. You will need to remove this bracket noting its position
and disconnect the pressure sensor.
Undo the 5 x 8mm bolts holding the fuel rail in position and remove it.
Very carefully remove 6 x spring clips holding the fuel injectors onto the fuel rail, this is tricky and you need to
hold the clips firmly to prevent them springing away. Carefully lever them off with a small flat bladed
Once the rail is removed you will see the fuel injectors exposed you can now gently twist each one to remove
it, you will also need to disconnect the electrical connectors. Ensure you label each injector with the respective
cylinder number so you know where it came from.
You can also remove all 6 of the ignition coil packs each has an electrical connector to disconnect and an 8mm
bolt to remove. Again label each one so you know which cylinder it came from.
If the spark plug socket gets stuck down the hole you might need to remove it carefully with some long nosed
pliers. Take care not to drop any debris down these holes as it will damage the engine.
Also remove each spark plug again noting which cylinder each plug came from, check the spark plug condition
against the chart provided and record your findings.
You should now have all of the ignition coil packs and fuel injectors out of the vehicle and on your bench for
testing and inspection. Visually check all of them for dirt, contamination and signs of electrical failure such as
tracking lines or cracks in the insulation. Check the electrical terminals for corrosion.
Set your multi-meter to 0-200 ohms range and connect the test leads as shown. This is made easy for you because we
know we are measuring 0-20 ohms. However if you did not know the range you need to start high and work you way
low until the readout looks credible. Once the meter is set firmly touch the test leads together to check for their
resistance and record it. You will need to add the resistance of the leads to your readings taken from the components.
Fit the test adapter cables to the fuel injectors electrical terminals to ensure you have a good connection with
Take a reading in ohms from each injector in turn and record your results for each one. You can compare the
readings against the manufacturers specification however a good test is to compare each one, they should be
pretty similar. This one is measuring at 14 ohms.
Rebuild the intake system in reverse order, you will need to put a little Vaseline around the injector seals to aid
fitting them. All of the 8 and 10mm fasteners have a tightening torque of 10 NM take care not to cross thread
the bolts particularly those fastening the fuel injector rail. This is what your finished engine should look like.
Once completed remember to check the coolant level.