Fuel leak under plenum

[GuidoInc]

1996 Q45 105K miles

I have to remove the plenum again. I had someone else do the work previously but someone at Scottsdale sent the hose kit for a 93 Q. Only some of the hoses could be used (next time I talk to Joe so no more errors). I have a coolant leak which I found and got the hose for it and there is also a fuel leak. I saw the leak on the passenger side near the rear of the plenum dripping off something just below the plenum. I know that fuel injector seals could be a cause. What else could be the cause? Does the fuel rail have seals?Thanks for your help.

[911/Q45]

There are about 3 short lengths of rubber hose connecting the hard fuel lines under there that dry up and shrink with age. Replace them with the best quality high pressure hose you can find.

[DougQ45]

Its sounds like your fuel pressure regulator is leaking, or the hoses on the fuel pressure regulator. Get a flashlight and check for leaks at start up. The leak mayl stop after the metal expands due to engine operating temps.

[squeefoo]

Use brand new high pressure / fuel injection clamps 10mm=3/8 with hex heads, I just remembered how easy those phillips strip!

[Aus94Q45]

Mine were leaking in that same area. Much more likely to be the hoses rather than the regulators. You can see the connections with a flashlight. I was able to snake various tools in to tighten the clamps. When they were replaced two years ago, apparently the mechanic put very light pressure on the hose clamps -- they turned on the hose when pushed with a screw driver. They have now stopped leaking. Its great to turn the heater and not choke on gas fumes at every stop light!

[GuidoInc]

Well I finally took the plenum off (ugh!). I looked where I saw fluid leaking before I took the plenum off and it is dripping off the metal base of where the fuel injector on the passenger side and nearest the fire wall. Could this be a seal? Does this require replacing the fuel injector? Any help is deeply appreciated.

ThanksBrian

[DAEDALUS]

Yes, sounds like an o-ring is leaking if you're certain it is coming from the injector. Seems the upper seal is the only possibility unless something is really wrong...it is the likeliest culprit. Make sure it's not the one of the rubber lines going to the fuel rail. You'll have to pull the injector out and replace both upper and lower seals. They're not too expensive. Careful cranking the engine after you're done, and make sure to release fuel pressure before pulling the injector out. Don't wanna hydrolock the engine with gas. Change the oil soon after as well.

[Aus94Q45]

Probably the o-rings on the injector. I would do them all if you have the plenum off. The o-rings are <$1 per injector. Also, as discussed many time, OHM check the injectors for resistance. DO a search for the procedure.