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Removing Rb25 Injectors

calaistur

By calaistur,
in General Maintenance

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calaistur Enthusiast

calaistur

Posted
Posted

Hi Guys,

Cant seem to find anything on this in these forums, so I am asking for some guidance.

I am wanting to remove my injectors for a thorough cleaning. Can anyone give me some instructions on exactly how to do this?

The basic steps I believe are:

Run the car and pull the fuel pump fuse to remove fuel in the system.

Remove the throttle body and top half of the plenum to get at the injectors and rail (amongst a bunch of other hoses etc).

Remove the rail and injectors.

Now the stuff I need guidance on is:

Will i need new gasket for the throttle body when it is removed?

How are the injectors held in place? Only by the pressure of the rail holding them in? or do they screw in?

Do I need new o-rings? How many? Best place to get them? What should I be paying?

Are there any traps I should know about?

I am happy to do up an instruction sheet with pics and post it here if I go ahead with it.

Any help here appreciated.

Justin.

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Godzilla32 Veteran

Godzilla32

Posted
Posted (edited)

If the throttle body gasket is still intact after disassembly apply some ultra blue silicone to it and it will ok. If in any doubt replace. Ask nissan, should be cheap as they are only paper gasket. Ive never taken injectors out of those engines but normally they are only held in place by the rail which is bolted to the inlet manifold. Hence they are sandwiched between. When you get your injectors cleaned professionally (only way to do it properly) they will supply you with all new o-rings and possibly insulators too. When reinstalling injectors make sure you use rubber grease or vaseline on the o-rings to prevent them from getting cut on insertion. When re-inserting use a twisting motion back and forth while you press them gently into the rail. Look to pay around $30 (plus gst) per injector for an ultrasonic bath clean and test.

Good luck

Deren

Edited by Godzilla32
MerlinTheHapyPig Mentor

MerlinTheHapyPig

Posted
Posted

you can also use silicone based lubricant.

and as deren said, you need to get them professionally cleaned! the 'ol mr jiffy ain't gonna cut it. They actually put the injectors in a test tank and open and close them at a certain frequency to clear out all the crap. usually $20-30 per injector at most fuel injection specialists.

As far as the gasket is concerned, probably best to replace it, you can buy gasket paper and cut them to shape if the nissan ones are expensive (as they usually are)

RANDY Veteran

RANDY

Posted
Posted

As far as the fuse and fuel thing... I wouldn't think it was wise. Running lean like that (even briefly) could cause issues. I guess the motive behind that is to release the pressure of the fuel?

Do it the next morning, and the fuel pressure will probably drop sufficiently, but put nice thick rags under the work-area just incase eh?

blind_elk Grand Master

blind_elk

Posted
Posted

Randy, it's what the workshop manuals say, so it can't be all that dangerous. (It's only a problem under load, when a lean mixture can cause detonation).

The rail is held in by 3 bolts. And it's not really necessary to separate the plenum - if you remove enough hoses and stuff, the rail will come out forwards (over the radiator).

Godzilla32 Veteran

Godzilla32

Posted
Posted
As far as the fuse and fuel thing... I wouldn't think it was wise. Running lean like that (even briefly) could cause issues.

Eh?? Lean? It mearly runs the engine out of fuel so it doesnt spray at you when you remove fuel lines.

  • 2 months later...
J_Red33 Experienced

J_Red33

Posted
Posted

My advice, take the injectors to be cleaned while still in the rail. Let them fully dissassemble it from there. They can be a tricky thing to get out without damaging them & they probably won't charge a lot more to do it if anything.

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