How to replace fuel injectors on TU3JP(KFV) engine.

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My Name: Ozvtr

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Posts: 1043
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
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I had cause to remove and inspect the injectors in my engine. So I decided to document what I did.
I have a 1.4I TU3JP (KFV) engine.

Parts of this procedure can be used if you need to remove the inlet manifold, the coil pack, the spark plugs or change the air filter.
injectors 001.jpg
injectors 002.jpg
injectors 002a.jpg
injectors 003.jpg
The first thing you need to do is remove the air cleaner box.
Remove the clamp holding the air cleaner box to the throttle body. Then remove the crancase breather pipe. Undo the air box retaining pin There SHOULD also a gasket under the pin holding it in place to the air claener box. Inside the outlet to the air cleaner box is a tubular gasket that forms a seal over the throttle body...don't loose it.
injectors 009.jpg
Remove the crankcase ventilation lines and the purge valve. Remove the two nuts fastening the earth wire and the purge valve bracket. Disconnect the purge valve electrical connector and vapor line. Disconnect the crankcase ventilation lines from the rocker cover and the inlet plenum. Press in on the yellow tabs to remove the connections. Remove the lines as an assembly.
injectors 010.jpg
Remove the remaining electrical connectors on the MAP sensor, coil pack and the throttle. There is a bar shape protrusion on each of the connectors, under each is the locking tab. To release the connectors. Lift the locking tab under the "bar" and pull the connectors apart. Unthread the electrical loom from the tabs on the coil pack.
injectors 013.jpg
Remove the special studs retaining the coil pack. These have integral nuts. Remove the coil pack.
injectors 014.jpg
Remove the three torx head screws holding the inlet manifold bracket in place. Remove the bracket.
injectors 014a.jpg
Remove the fuel line from the injector rail. Caution: a small amount of fuel will come out under pressure.
injectors 015.jpg
Remove the two torx head screws holding the injector rail to the cylinder head.
injectors 019.jpg
Remove the brake booster vacuum line from the back of the inlet plenum.
injectors 020.jpg
Remove the brake booster line from the clip on the back of the inlet manifold.

Continued in part 2.
User avatar
My Name: Ozvtr

Moderator
Posts: 1043
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
Has thanked: 44 times
Been thanked: 300 times

Post

Part2

injectors 023.jpg
Remove the electrical connector from the injector electrical loom on the back of the inlet manifold.
injectors 023a.jpg
loosen the five nuts holding the inlet manifold onto the mounting studs. Undo the nuts to the edge of the thread on the studs but dont remove them just yet.
injectors 030.jpg
Work the injector rail in and out to loosen the orings on the injectors inside the head. They may be very stuck but keep at it.
injectors 030a.jpg
If you can remove the injector loom from the clip on the inlet manifold in situ or the clip is just missing you can remove the fuel rail with out removing the inlet manifold. Caution: the injector rail is full of fuel,about 1/2 a cup full.

I found it easier to remove the five nuts and then remove the inlet manifold and injector rail as one piece rather than try and jiggle the injector rail out from inside the inlet manifold because the injector loom was attached to the inlet manifold by a clip (see photo of loom connector above).

If you remove the entire assembly you may find that the injector loom connector is connected to the inlet manifold with a clip. Get your finger nail or screwdriver between the clip and the electrical connector and slide the two apart.
injectors 100.jpg
The injector rail assembly pulled apart. All the clips and connectors come apart fairly easily.
injectors 110.jpg
When you replace the injectors use a thin smear of petroleum jelly on the orings to lubricate them.
injectors 120.jpg
injectors 125.jpg
Install the clip onto the groove in the back of the injector. Insure it engages onto the locating tab.
injectors 130.jpg
Line up the two tabs on the injector and manifold. Press the injector into the fuel manifold until it clicks in place.
injectors 140.jpg
The completed assembly.

Reassembly of everything is in the reverse order.

The injectors "squirt" a small amount of fuel into the inlet valve area of the cylinder head which mixes with the air and is sucked into the cylinder on the intake stroke. This amount is controlled by the engine ECU. The amount of fuel required is determined by the demand on the engine. The volume of fuel is controlled by how long the injector is open or turned on. The engine ECU is fairly smart but it only has so many resources to check if the engine is running correctly. If there is physical damage to the injector the engine ECU will try to compensate but that might do more harm than good. Two of my injectors were blocked by matter in the outlet orifice. It must have come from the inside of the injector? There are fine mesh filters on the inlet of the injectors, so it cant have come from the fuel supply. Gum and varnish in the fuel system can stop injectors from working properly under some circumstances. Unfortunately the engine ECU attempts to compensate for bad injectors and the incorrect fuel ratio can cause carbon build up in the "good" cylinders and over all poor performance. This could be very gradual and you may not notice it. However my old friends the spark plugs will tell you a lot about your engine. For example, in his case, if you have one or more bad (blocked) injectors the "good" cylinders will have sooty plugs because the engine ECU will be over compensating with fuel into the good injectors. So pull your spark plugs out at each service, that will tell you a lot about your engine. They should all be about the same as far as looks go, a light dusty coat of deposits. No crust and not black. Slightly sooty is OK.
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