Fuel injector sounds like it's leaking air...

[mhuffman]

I did a pressure test earlier today. It also sounds like there is air leaking out of the #2 and #3 injectors.

How are the injectors tightened into the intake manifold? Where can they leak from?

 

[ROOKIE1]

The lower seals dry out over time .http://www.slowboyracing.com/estore/product.php?productid=2069&cat=1060&page=1

 

[robbo185]

the o-rings can leak if they are worn/old/ installed wrong

 

[mhuffman]

The lower seals dry out over time .http://www.slowboyracing.com/estore/product.php?productid=2069&cat=1060&page=1

Are these different from the ones that go in between the injector and the fuel rail?

 

[ROOKIE1]

They should be . You may have to check dealer for upper seals .

 

[kenamond]

The link above is for injector insulators. These seal the injectors to the head. As was mentioned, they degrade over time and will leak boost (they are plugged into the intake runners which are pressurized under boost). The injectors seal to the fuel rail with o-rings. If the o-rings leak, it's not air, it's fuel. While you have the fuel rail off, you might want to replace the injector o-rings at the same time.

Check out the tech article on this for some additional information you might not think of.

 

[mhuffman]

Sweet thanks everyone!

 

[mhuffman]

Hey everyone, i was able to remove the lower insulators without de-pressurizing the fuel rail! All i needed to do was remove PCV, intake manifold/throttle body brace, and unhook a few electrical connectors and i was able to lift the fuel rail up about 4 inches, enough to remove the injector insulators. it was alot easier than what others here have done, and easier than the FSM too.

 

[project95gsx]

Hey everyone, i was able to remove the lower insulators without de-pressurizing the fuel rail! All i needed to do was remove PCV, intake manifold/throttle body brace, and unhook a few electrical connectors and i was able to lift the fuel rail up about 4 inches, enough to remove the injector insulators. it was alot easier than what others here have done, and easier than the FSM too.

Thanks for following up on this, I'll be doing this soon. I get a whine while driving after 10 pounds so i did a boost leak test. I heard a hissing and smelled fuel near the injectors, I can wiggle my injectors and the hissing stops. Thanks again.

 

[mhuffman]

Thanks for following up on this, I'll be doing this soon. I get a whine while driving after 10 pounds so i did a boost leak test. I heard a hissing and smelled fuel near the injectors, I can wiggle my injectors and the hissing stops. Thanks again.

If you also smell fuel and you think it's from the injectors, you'll probably want to replace the o-rings and the insulators. Insulators will stop the boost leak, o-rings will stop the fuel leak (if present). Since you'll be in there, you'll just have to de-pressurize the fuel system and you can do both things at the same time.