Removal of injectors

[pitpan]

Hi all,

How do the injectors come out of a MF49 KFX 1.4 engine.

Do they just pull/screw out easily or Is it necessary to use a injector puller

The Haynes book says just lift them out but I'm not too sure.

Thanks

Pitpan

[Gadgetman]

You just pull them out.

You may want to clean the area around them first, to avoid dirt getting into the holes.
(And plug the holes with rags or something if you're not reinstalling injectors immediately)

They're not all that tight, really. Twisting them a few degrees clockwise/counterclockwise as you pull them up may help a bit as they can 'grow stuck' as the seals age.

Inspect each injector as you remove it to verify that the old seal is still on the end of the injector.

[pitpan]

Thanks gadgetman,

Yes I wil use a small compressor I have to blow all the dirt dust etc away. I will be putting in new ones straight away so will be very careful to check for old seals have been removed.
so there not like the ones you see on you tube which have to be removed with a tool

Pitpan

[ffrenchie]

They are petrol injectors in your engine, are you getting them confused with diesel injectors ? Yours will probably just have a rubber O ring on the stem and pull out of the inlet manifold while diesel ones go into the cylinder and get gummed in with carbon.

[Gadgetman]

Well, if you don't have any experience with gasonline injection, or have only touched diesel injection systems, it's probably a common assumption that the injectors needs to sit tightly.

The TU3 engine uses 'wet manifold' batched multipoint injection.
(The injectors fires in pairs, spraying fuel into the inlet manifolds, close to the inlet ports of each cylinder)
They're not in contact with any high-pressure areas like you'd expect in a 'direct injection' system where the fuel is sprayed directly into the combustion chamber.

More modern gasoline engines may have 'direct injection', though...

In theory, it should be possible to rebuild the engine from 'batch' to 'sequential' firing of the injectors, by swapping out the ECU and part of the wiring loom. This may give a slight improvement in fuel economy. (But the electronics and work will probably cost more. )

http://en.wikipedia.org/wiki/Fuel_injection

[pitpan]

Thanks for the great info chaps, its very good that some folks on here are helpful in their answers.

Now I feel that I can tackle this small job with the knowledge that you have supplied.

Thanks to dumdum too for his input on depressurising the fuel line , because I was going to pull the line from the rail but his input saves me from getting fuel everywhere and is safer.

cheers guys.

pitpan.

[dumdum]

Pleasure bud! It's easy... I undo all the bolts holding the rail in including the support bracket in the centre, then gently lever at one end and wiggle the rail back and forth to free the well established seal between injector and inlet manifold, then once out there's clios on each injector holding it to the rail