fuel leak though intake why

[noslow1986]

i have a leak im using a trick flow 1 inch spacer inbetween my upper and lower intake and the back side towards the windshield is wet on both sides on the spacer bolts are tight. should i take the spacer off. im thinking this might give me a vacuum leak no sure though. what do u think

 

[mackey]

It is probably leaking out of the top of the rail where the injector meets it. You should replace those o-rings and check that out. The fuel goes down with gravity so it owouldn't leak up through the intake.

I run the spacer and no problem (3/8")

 

[noslow1986]

would it leak on both sides of the intake gasket. i replaced the o ring on the injectors about a year ago. i guess i will have to look at it tommorow. i think this might be my vacuum leak. what size is the two top bolts using a trick flow intake. i need the socket size.

 

[mackey]

Well the screws that hold the fuel lines down in back might have come off. This would allow the back to lift a bit and cause the fuel to leak out.

I am not sure what size the screws are, but they are 12 Point, Maybe 5/16"?

 

[mackey]

I'm not sure if it would cause a vacuum leak though. Probably not if the injectors are sealing off the hole.

 

[daddystang]

noslow1986, Are you saying that when you take the upper intake off the gasket and spacer are wet on the inside on the back half of the intake? Mine is doing exactly that also. Hopefully someone else has had this problem and can offer a fix.

 

[jrichker]

Wet fuel inside the intake is from a fuel pressure regulator that has a ruptured diaphragm. One side of the diaphragm has fuel under pressure and the other side engine vacuum. Guess where the fuel ends up when the diaphragm leaks? In the intake manifold and vacuum line connected to the fuel pressure regulator.

 

[daddystang]

I don't have fuel in the vacuum line, do you think it could still be a ruptured diaphragm? Why would just the back four intake runners be damp inside? I never thought about the regulator, because it's a BBK, and only about eight months old. But,,, it's true with most things, just because it's new, doesn't mean it's good. Thanks jrichker...

 

[noslow1986]

mine leaks from the back of the motor i have a spacer on the back and u can tell its wet, it has a darker cooler then the rest of the gasket. today i lifted the gasket and could smell the fuel. time to put on my fuel pressure reg

 

[jrichker]

Remove the vacuum line from the regulator and inspect for fuel escaping while the pump is running. If fuel is coming out the vacuum port, the regulator has failed. Check the regulator vacuum line for fuel too. Disconnect it from the engine and blow air though it. If you find gas, the regulator has failed.