Unknown underhood fuel leak

[hugo2go]

I think that means your supercharger needs to come out.
I'll be gladly to take it off your hands.....

But on a serious note, my buddy had the same thing happen. replace the FI O-rings.
Better to be safe than have a fire under you hood.

 

[thatoneguygeoff]

All of the injector seals are new. I had a new engine put in about 5 months ago and the fuel leak was there prior to the swap.

 

[GSPRunner]

As I stated before I'm having the same issue. Replaced all the FI o rings on Saturday and still having the issue. I'll be curious to see what you figure out.

 

[azcat90]

Dry?

I don't understand when you say dry - the gas is a vapor when it escapes the FI chamber so it would never be wet.

 

[thatoneguygeoff]

So I just looked under the hood and that dried gas residue is back. So I drove to my mechanic to show him my findings and he agrees that it could very well be the fuel line having a crack and seeping through the crimp. Now to find time to replace the fuel line...

 

[thatoneguygeoff]

And by dry fuel azcat90, ever see gummed up old fuel in a carburetor bowl? Its the same gummy brown residue youd see in there.

 

[rideexileex]

Hmmm.... Now the decision to buy OEM or just to build it your/my/ourselves? I've already cut my primary fuel line when installing the 7th injector. Might be cheaper to just buy a banjo end and the fuel hose. This would be an awesome, easy fix. Might as well do them all while in there. Can you tell if its the primary or the cross fitting that's leaking?

 

[thatoneguygeoff]

Its the main fuel supply line to the fuel rail

 

[thatoneguygeoff]

Deleted

 

[GSPRunner]

Deleted

Deleted? Like you fixed it or what?

 

[thatoneguygeoff]

Deleted as in I added a comment into the wrong thread and don't know how to delete the post from my Ipad lol

 

[rideexileex]

Any progress?

 

[A.Wilson013]

[MENTION=82154]GSPRunner[/MENTION] and I are chasing this EXACT same issue on his 4Runner.

-Replaced the o-rings on the injectors (though they didn't seem to be in poor condition)

-Replaced the "supply" line that feeds the passenger side of the fuel rail from the hard line on the body.

Neither of these fixed the issue.

I believe that the next logical step will be to replace the line that goes into the FPR... Thoughts?

 

[thatoneguygeoff]

Nothing yet. I'm out of work on medical leave from having eye surgery yesterday. I'm hoping to dig into this hard when my vision returns.

 

[thatoneguygeoff]

Leak found!!! It turns out that it is the fuel pressure regulator itself that is leaking. Gonna get it swapped out tomorrow! Finally an answer!

 

[RedSled]

Leak found!!! It turns out that it is the fuel pressure regulator itself that is leaking. Gonna get it swapped out tomorrow! Finally an answer!

Glad you found it man, thanks for letting us know what it was.

 

[rideexileex]

Odd question, but did you ever experience a 'whistle' when under boost/heavy load?

 

[thatoneguygeoff]

The only noise my 4Runner makes under boost is the whine of the supercharger lol. Your whistle sound could be from your intake depending on what kind you have with not having enough air flow to feed the supercharger.

 

[GSPRunner]

Odd question, but did you ever experience a 'whistle' when under boost/heavy load?

I get a distinguishable whistle but only when I'm at partial throttle...

The only noise my 4Runner makes under boost is the whine of the supercharger lol. Your whistle sound could be from your intake depending on what kind you have with not having enough air flow to feed the supercharger.

Glad you found your leak finally. Did you replace all the lines leading up to it and the o-ring as well? I am replacing just the lines and o-ring tonight hoping that will fix my leak.

 

[thatoneguygeoff]

The lines seem to be in good shape still so I won't replace them until they get bad. Also, while the supercharger is off I'm going to replace my cylinder 1 fuel injector to eliminate my intermittent P0301 code.