fuel leak problem

[wingman]

Just throwing this out there real quick to get some more information before I go assuming stuff, but I have a fuel leak somewhere on the rail. There's a tiny puddle of fuel in every dip for the mounting bolts after a short period of idle, not just the one closest to the feed line which throws me off of the leaking hose track. I'm running RC 550 injectors and an aeromotive AFPR. I'm looking for any advise possible right now because it's my current DD and I work a 60 hour week, so getting to work and getting there on time is critical.

Could it be a bad seal between the injectors and rail? Would that cause fuel to make it's way up to the top of the rail? Is there any way fuel can escape through the top of the rail should the mounting bolts come loose? There is a nice puddle of gas left when I park my car, and 70 miles to half a tank with very little boosting doesn't fly.

 

[jdub]

Fuel has a nasty habit of running along the rail...the fuel pooling in the clearance slots actually points me to the fittings. Check the fittings...I used teflon paste (got it at ACE Hardware - don't use teflon tape) on the theads that screw into the rail. If you removed the FPD, that fitting too. If these are AN type fittings, don't use the teflon paste on the AN side.

The fittings are easy to check...if it's not them, check the O-rings on the injectors.

 

[wingman]

that was my first thought, as after looking it over the majority of the fuel was pooled in the slot closest to the feed line. Hopefully I can get out a bit early from work tomorrow and burn some daylight figuring it out. I'll go and snatch some teflon paste from a buddy tomorrow too.

another question, how well do AN fittings cope with flow changes and vibration? It didn't seem to leak until just in the past few days, or at least that was when I first started noticing the tiny pools and the fuel smell. Anybody have a quick referance as to what torque setting they should be dialed in to? $2.60 a gallon adds up awful quick when your dropping it on the ground and I'd like to go in there and fix it right the first time.

 

[jdub]

AN fittings don't have a specific torque setting (as far as I know), but I do know you don't want to excessively tighten them down either. Mine are about a quarter turn past finger tight. AN fittings seal on the 37 deg cone that mates together. They resist vibration very well.

 

[wingman]

alright I understand now....maybe they just weren't torqued down enough and came a little bit loose. I'll probably take them off, clean them, and throw them back together and see what happens.

 

[blacklightnin55]

Why not use teflon tape on the fittings?

Fuel has a nasty habit of running along the rail...the fuel pooling in the clearance slots actually points me to the fittings. Check the fittings...I used teflon paste (got it at ACE Hardware - don't use teflon tape) on the theads that screw into the rail. If you removed the FPD, that fitting too. If these are AN type fittings, don't use the teflon paste on the AN side.

The fittings are easy to check...if it's not them, check the O-rings on the injectors.

 

[jdub]

Why not use teflon tape on the fittings?

Teflon tape will shred as you screw the fitting in. Even though it's unlikely, if a piece breaks off inside the fuel rail, it will go in an injector and trash it...permanently. Even with teflon paste, you want to leave the bottom couple threads bare...when you screw the fitting in, the paste will migrate up on the threads and leave a small bead at the top when the fitting seats. You want to use just enough paste to coat the threads...not too much.

 

[Supraholic]

I had the same problem after my 550 install. well, there was fuel all over the rail and fuel smell in the car.. it was the fuel pressure damper at the feed side of the rail. fuel was somehow leaking into the plastic cover and leaked out.. i replaced the damper unit with a used one from someone in the forum, and never had the problem.. worth checking out..

 

[3p141592654]

Fuel injectors have internal filters. Its standard procedure to replace them when injectors are cleaned/flow tested.

Teflon tape will shred as you screw the fitting in. Even though it's unlikely, if a piece breaks off inside the fuel rail, it will go in an injector and trash it...permanently. Even with teflon paste, you want to leave the bottom couple threads bare...when you screw the fitting in, the paste will migrate up on the threads and leave a small bead at the top when the fitting seats. You want to use just enough paste to coat the threads...not too much.