Unknown underhood fuel leak

[A.Wilson013]

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.

Where was the FPR leaking from...? How were you able to find the leak?

 

[thatoneguygeoff]

Where was the FPR leaking from...? How were you able to find the leak?

Directly below it there is dried fuel residue. I posted a picture of it a few weeks ago of the residue. The associated fuel lines and all other fuel connections are residue free and since the leak only occurs under boost when the fuel pressure increases, it lead me to the conclusion that the fpr was/is the weakest link. I also confirmed this with my mechanic this morning and he said that he's seen this issue a few times before on supercharged high mile 3.4's.

 

[azcat90]

Ouch

Hope your eye's OK...

 

[GSPRunner]

I'm happy to report that my fuel leak issue has been solved. Replaced the fuel lines to the FPR and the O-Ring and no more fuel smell. FINALLY.

 

[xvbnxh]

I have no experience, but my first thought is leaky injectors.

 

[gamefreakgc]

Directly below it there is dried fuel residue. I posted a picture of it a few weeks ago of the residue. The associated fuel lines and all other fuel connections are residue free and since the leak only occurs under boost when the fuel pressure increases, it lead me to the conclusion that the fpr was/is the weakest link. I also confirmed this with my mechanic this morning and he said that he's seen this issue a few times before on supercharged high mile 3.4's.

That's a good mechanic you have! And the fact he's seen multiple supercharged 4Runners. Second time this week someone has replaced a FPR due to leaks, when before then I've never heard of a Toyota FPR going bad. Weird.

 

[GSPRunner]

That's a good mechanic you have! And the fact he's seen multiple supercharged 4Runners. Second time this week someone has replaced a FPR due to leaks, when before then I've never heard of a Toyota FPR going bad. Weird.

Mine was leaking from the FPR, but just needed to replace the o-ring on it. I'm guessing he probably needs to do the same as I'm not sure where else it could be leaking from out of the FPR.

 

[AntleredRuin]

Mine was leaking from the FPR, but just needed to replace the o-ring on it. I'm guessing he probably needs to do the same as I'm not sure where else it could be leaking from out of the FPR.

I believe gamefreakgc was talking about my rig. I haven't been able to replace it yet as it shipped about a week and a half late, but my FPR is leaking THROUGH the vacuum line into the Air Intake Silencer. I can remove the silencer after every time I drive and dump at least a few fluid ounces of fuel out. Mileage is HORRIBLE, and the smell is pretty overwhelming when I get on the gas.

 

[thatoneguygeoff]

Haven’t posted here in a long while and that’s changing haha. So the actual fuel leak was a missing check valve that goes on the fuel rails vacuum line y assembled. Basically there is a vacuum line on the back of each fuel rail that goes to a y connector and then to the bottom of the throttle body. When the supercharger is installed you add a little plastic check valve in line so the boost doesn’t back feed to the throttle body. I ended up talking with someone at Magnuson and was able to pick up the check valve at Autozone for a whopping $3 for a pack of two haha. Installed it and the leak is gone for good!


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