Fuel injector leaking air???

[Mordred]

Hey,
Recently my first fuel injector was leaking so my first idea was to replace the injector. After having replaced it the injector was leaking air, a very loud hissing sound no doubt coming from the injector.
I figured the injector I had replaced it with was incorrect and after reading in my manual that u should replace the seal I went out and bought one, put it on a another injector. This time I removed the entire fuel rail just enough so that I could fit the injector on. To my horror after having done this, the air sound is louder and my car will stalls unless I keep my foot down.
Whilst I keep my foot down it starts to backfire through the air filter, have I forgotten something important here? Do I need a brand new injector? is there something wrong within the head itself? Please help.
Note: My car is duel fuel and runs ok on gas so it seems to be solely a fuel related issue.

[Hillerus]

You sure you don't have a vacuum leak somewhere?

Injectors tend to leak fuel if the injector O'ring isnt sealing.

[Mordred]

how can I check for a vacuum leak effectively?
I'm almost positive that the injector is leaking air, from where it goes into the head.
I may have the wrong sized injector do you think?

[harry3]

sounds more like air being sucked into the intake manifold

[jatsvl]

because you removed the fuel rail and your injector seals are probably old and brittle so when you replaced the rail they don't seat/seal anymore, maybe you should have replaced all six seals I beleive that is recommended when you remove your fuel rail

[bradcad]

My trick- works a bloody treat. Get a bottle with a plastic hose- those self bleeder kits from stupercheap for about $8 work brilliantly. They also have a fine tip which helps.

fill with water, start the car and get her idling. Fast idle will also do. Put just a couple of drops on the base of each injector. If there is a leak, the revs will drop dramatically. You can use this process for all areas before combustion- around the throttle body, intake hoses, vaccuum hoses, manifold gaskets. I found a few leaks when bloody mechanics told me there were none.

[Not_An_Abba_Fan]

You sure you don't have a vacuum leak somewhere?

Injectors tend to leak fuel if the injector O'ring isnt sealing.

They will leak fuel on the rail side of the injector, but where it goes into the head it will suck air. It fires into the head as the intake valve is opened so the fuel air mix gets sucked into the engine. If the seal on the injector is buggered or the injector isn't seating correctly, it will result in a vacuum leak.

The water trick will work, and it's free. Another way to do it is to get some aerostart and spray the base of each injector while its running, if the revs pick up, that's the one that is leaking.

Just check the purge hose on the bottom of the throttle body, if that has come off or split it will sound the same, and run like a bastard.

[toddwold]

Maybe I am missing something here, but I recently replaced my fuel injectors and 2 are leaking air at the base. Is there something I can use to seal the threading or is this normal? There are no o-ring seals here, only where the fuel lines attach to the injectors, but not where the injectors screw into the head.

[Munz]

Pretty sure new injectors come with fresh O-rings.... well mine did

[toddwold]

Yes, came with new o-rings. Used lock tight to seal the air leaking at the base of the injectors. The 0-rings are at the top where the fuel lines connect to them, not at the base where it threads into the engine. Now, trying to figure out why so much smoke. Looks mostly white, but might be slightly blue. No air in the radiator and not pulling radiator fluid. Trying some oil sealant additive to see if it's the seals. A diesel mechanic told me he's never seen the timing go out on these. Maybe the injector pump? But if it's leaking at the injectors, then the injector pump must be working.

I have run straight used vegetable oil in it. Maybe I clogged the line from the fuel tank. It has a new fuel lift pump, but maybe if the line is clogged, it's running lean?

Thoughts?

[jatsvl]

Yes, came with new o-rings. not at the base where it threads into the engine. Now, trying to figure out why so much smoke. Looks mostly white, but might be slightly blue.

I have run straight used vegetable oil in it. Maybe I clogged the line from the fuel tank. It has a new fuel lift pump, but maybe if the line is clogged, it's running lean?

Thoughts?

geez mate, this is a GM holden VL forum most of the discussions here are about 304's and RB30's (6cyl nissan engine) which is described above. and the injectors seat into the head and don't screw in, somebody maybe able to help you but these are petrol engines we are generally discussing. welcome and I hope you solve your problem.

might I redirect you to somewhere like this:
http://www.exploroz.com/Forum/Topic/..._problems.aspx
or here:
http://www.truckforums.com/forum/ford-f-250-forum-17/

[detox_nath83]

vege oil LOL its not a Diesel, or the diesel project car running on used chip oil.(Top Gear)

the o-ring sits in the intake runners injector holes and the Injector Pintle (plastic spray nozzle on Inj) slides in so the o-ring is around this nozzle making a seal.. that's where ur leak is,,,

or as stated u have a vac leak around the throttle body/plenum chamber..