New injector O-ring still leaking ALOT of air

[4BangerV8Killer]

I recently did a boost leak test on my car because and found a VERY large leak on my number 4 cyliner coming from the lower O-ring of my injector. I bought new rings pulled off my fuel rail replaced them. During so i found that one of my denso 720's had a slightly melted notch in the tip of it....guessing thats not good at all. Anyway I figured this was going to be an easy fix because my leftmost rail bolt was snapped off and broke inside so it had no bolt there and I was assuming that was the cause of my leak. So I drilled out the bolt, changed the O-rings and bolted it all down. Now the leak is just as bad if not worse because now when my engine is coming down in rpms it backfires terriblely. Why isnt the injector sealing properly? should i put some silicone in there or rubber gasket?

 

[yokotabrat]

No, I wouldn't use any silicone or RTV. The factory seals should work perfectly. The things to check:

Do the seals fit snug on the injector where you're having problems? When the seals are new, they're a snug fit on the injector and shouldn't be really easy to slide on and off.

Do the seals fit snug in the hole of the cylinder head?

Are you sure the injector seal is leaking and not the intake manifold?

Is the pintle on the injector melted above (away from the cylinder head) where the rubber gasket seals again the injector? Maybe try leaving the seals in the same locations and swapping just the injector to see if the leak follows the injector.

Did you torque the fuel rail bolts down to factory specs with a torque wrench?

 

[4BangerV8Killer]

i dont have a torque wrench but they are on there pretty tight and its not the injector thats causing it to leak cause i put the injectors in different order this time and the o rings fit snug. it just looks like the o ring isnt being pushed down as far as the others but the bolts are as tight as they are gonna get without snapping them...which iv done twice tonight . idk how to get the injector to seal any tighter. and the melted part is below the oring...its between the oring and the head

 

[yokotabrat]

Maybe there is some piece of the old seal leftover in the cylinder head under the new seal? Try installing the seals into the head first, verifying they are flush with the head, and then install the injectors.

 

[4BangerV8Killer]

ok ill have to check that out tomorow ill get back to you thanks for the help though

 

[4BangerV8Killer]

on second thought i remember looking in there and seeing it was cleaned up because we had to drill out that bolt right there so theres nothing keeping it from sealing that i can think of...i just cant get enought pressure on it from the injector and the bolt is as tight as im gonna get it!!!! idk what else to do