Mysterious Fuel Leak

[walt]

I had my 3.6 conversion up quite high on rear jack stands for a few days looking for a rattle. I set the car back down and backed out of the garage leaving a trail of fuel behind me. In half a minute probably 1/2 cup of gas dripping near the right rear sway bar mount. Pulled it back in the garage and a few hours later tried to find the problem but nothing and no longer leaking. Anyone experience this? I've had the rear raised many times in the past, but this is a first.

[PeteKz]

What induction and fuel system are you using?

[walt]

Originally Posted by PeteKz

What induction and fuel system are you using?

This is a stock system from a 91. Years ago I had a bad fuel pressure regulator that leaked into the resonance chamber and finally out on the engine block. The symptoms are very different here.

One other thing, I never top off the fuel tank to the very top except this one time but, don't see why that would matter.

[PeteKz]

Yeah, I don't see why jacking up the tail end would cause gas leaks at the rear. You will have to run the pump or start the engine and see where it's coming from.

[walt]

No leaks found so threw a fire extinguisher in the car and continued to drive it. Then, after 3 weeks I start the car and the revs go sky high and settles back down after no more than a second. Pull out of the garage and have my second major fuel spill. Open the decklid and see fuel dripping from the air filter. Thinking the only way fuel could get into the intake is thru a faulty fuel pressure regulator, I pulled a vacuum on the FRP diaphragm and it checked good.

It's always been a bit hard to start if it sits more than 3-4 days but other than that it runs great.

[BoxsterGT]

The 964 Air Box & Filter are on the right side, above where the Fuel Feed connects to the Fuel Rail......



I would pull off the Air Filter Cover and carefully inspect the Feed Hose and the Main Tee.....



Since this is an engine transplant I suspect there is an issue with the hoses and fuel is collecting in the Air Box.

Are they factory original?

Len

[walt]

Len, I just finished removing the intake manifold to get a better look at everything. Unfortunately, I am not finding anything unusual with all the hoses and connections in good condition and tight.

What I can't explain is why this is an intermittent leak and when it does leak it's like spewing out of a garden hose (literally) and hitting the firewall. After the last leak I had someone sit in the car and start it a dozen times with me watching and not a drop.

Also, I don't have an airbox but an aFe flow pro filter. The main supply hose coming from the fuel filter is stainless steel braided. Thanks for any suggestions going forward.

[walt]

Think I found it. Looks like the rubber from the co-line hose is extruding out the front end of the ferrule on the one side.

[BoxsterGT]

WooHoo!

Discovered BEFORE a disaster!

Len

[pmax]

Originally Posted by walt

Think I found it. Looks like the rubber from the co-line hose is extruding out the front end of the ferrule on the one side.

Seems unusual for a line to bust out of the ferrule.

Should that be aligned ?

Not familiar with the 964, why is that bracket shaped like that with a "hole" ?

[BoxsterGT]

walt-

This is not rubber hose. It is Polyamide tube and cannot be repaired with hose clamps.

Once you remove the Tee assembly, post a clear photo so we can evaluate this.

I have made up a fixture for these 964 Main Tee assemblies.....



and would be happy to help.

Please email me for info.....len.cummings @ verizon.net but without the spaces.

Len