Replacing 3.0 Injectors and O rings

[Walko]

Is it possible to replace both o rings that hold the injector and assembly into the intake runners on a 3.0 SC motor without removing the manifold / motor from the car.

How often should the orings be replaced?

Thanks

Michael

[Scott R]

Originally Posted by Walko

Is it possible to replace both o rings that hold the injector and assembly into the intake runners on a 3.0 SC motor without removing the manifold / motor from the car.

How often should the orings be replaced?

Thanks

Michael

It sure is, however you need to be careful. The orange bungs usually disintegrate when I remove them, that's if they don't come out with the injector.

If the do remain in the runner, and remain complete you still have to exatrct it to replace the o-ring. But why? The bungs are cheap so just replace them as well. The real issue is dropping little pieces of broken plastic into the heads, so you have to weigh the risks.

If it where me, I would remove the system and re-seal it entirely. You can get the whole unit out in about an hour with the right tools. Then you can replace the breather gasket, t-stat o-ring and pressure switch for good measure.

[Walko]

Scott,

now you have me totally confused. Are you suggesting that it is quicker to remove the fuel head and intake runners and then push out the steel injectors?

Thanks

Michael

[Al S]

To remove the orange plastic injector sleeve you have to grind away 3 "staked" areas of the aluminum housing. A dremel tool works good here, although the rear cylinders are difficult (you need a small mirror). Make a wire hook that fits thru the sleeve, and hook the bottom to pull out. Restake the alum housing with a pin punch after reinstallation.

[Scott R]

Originally Posted by Walko

Scott,

now you have me totally confused. Are you suggesting that it is quicker to remove the fuel head and intake runners and then push out the steel injectors?

Thanks

Michael

You're dealing with two o-rings here, the one on the steel injector, and the one on the injector bung. I'm willing to be a few of the bungs will come out with the injectors, and a few will need to be extracted. Like Al S stated you have to remove the tabs and pull the bungs out, and it's not always easy, and can result in junk falling into the heads.

I saying that it's safer to remove the unit, and it allows you to do more in the way of a complete re-seal.

[Al S]

Michael, I've replaced the injector sleeve O rings on several 3.0's as per my previous post. It's not that bad, just takes a bit of patience. It's a heck of a lot easier than removing the entire CIS unit. Just stuff the hole in the sleeve before grinding, to keep the crud out.

[Walko]

Ok,

I think I understand the way forward. I want to replace the orings on the bung as well. So if i pull the bung out then i can easily pull the injector out on teh bench.

The back two bungs won't be a problem as they have already blown out and the orings replaced.

Thanks for your assistance

Michael

[Ricks911s]

. . . what is the harm of pulling it out injector sleeves with the system "AS IS"? ('76 911S) . I'm extremely worried now, because I pulled ALL of the injectors and sleeves to see what sort of leakage I might have. Several injectors came out WITH sleeves (& O-rings) some didn't. Did I make an expensive mistake??

[Scott R]

Originally Posted by Ricks911s

. . . what is the harm of pulling it out injector sleeves with the system "AS IS"? ('76 911S) . I'm extremely worried now, because I pulled ALL of the injectors and sleeves to see what sort of leakage I might have. Several injectors came out WITH sleeves (& O-rings) some didn't. Did I make an expensive mistake??

No, that's normal. It's just that I have seen where people try all means of extraction on the stuck bungs, this can lead to debris falling down into the heads, e.g. ground metal, broken plastic and such.

[Ricks911s]

Scott R -

Thanks for clarification. I'm a young guy and watch my pennies. And my car still has a ways to go . . .