Incurable Fuel Leak

[broncc]

I'm coming to the TRS in a time of desperation. I have tried probably five times now to seal my fuel pressure regulator to the fuel rail with no luck.

This is a 1994 motor. I didn't replace the regulator during the rebuild and it naturally had a rust failure 5,000 miles later. With the motor now in the car and the magic let out, I cannot insert the new regulator without cutting the o-ring. I have tried excessive amounts of grease (no molly compounds in it for clogging reasons) and even cleared any corrosion on the taper with some Scotchbrite. I'm running out of spare o-rings!

My question to you all is; how do you do it? I'm getting so sick of smelling raw fuel all the time. I really don't want to take the engine out or undo the intake...

 

[SenorNoob]

Are you sure it's right o-ring?

We use dish soap on them at work.

 

[superj]

we use crisco when building turbine engines because it mixes into the fuel and oil without causing problems.

 

[superj]

and you can get those in the plumbing section at your local hardware store to hold you over if you need more o-rings. they aren't "proper" car part material but i ran them on the fuel injectors in my bmws for autocross for years

 

[broncc]

I'm finally back and able to focus on this car again. I'm home sick and managed to slink to the garage to measure my o-ring set...

OD 0.571"/14.5mm
ID 0.295"/7.5mm
WD 0.140"/3.5mm

I'm beginning to wonder if this is actually a set of fuel injector o-rings. I am unable to recall or find a receipt where I got this unlabeled bag.

 

[2011Supercab]

OD 0.571"/14.5mm
ID 0.295"/7.5mm
WD 0.140"/3.5mm

I'm beginning to wonder if this is actually a set of fuel injector o-rings. I am unable to recall or find a receipt where I got this unlabeled bag.

You might be right,
Here are the injector O-ring measurements

I can't find anything on the size you need

 

[lil_Blue_Ford]

Seems to me like there has to be some sort of edge somewhere that you’re catching with the O-ring. I’d really go at trying to make sure the taper and seat area for the O-ring is as smooth as possible. Smooth is important, an O-ring by nature will seal against minor imperfections as long as it doesn’t get snagged and torn.

Unless the O-rings for the FPR are different than injector rings and they’re just way wrong in size… but that still looks like you might be snagging a burr somewhere…

I’ve started using Vaseline on O-rings…

 

[superj]

in the plumbing section, where you get the parts for your faucet, are o-rings in many many different sizes. i brought my stock old hard o-ring and found one that looked similar. it was little thicker and works great

 

[bobbywalter]

i would use the help section at the parts store

 

[bobbywalter]

GP Sorensen Fuel Pressure Regulator 800-93004

Shop for GP Sorensen Fuel Pressure Regulator 800-93004 with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

 

[broncc]

I wanted to update the thread with some new findings. I got a really good look at the problem when I had the engine out. It seems that the o-ring is not the issue. Its the bubble-and-taper joint on the fuel return. I had much better leverage from this angle and I really cranked it down as tight as I was brave.

Spoiler

(I know this is wrong for many reasons, but I put some ptfe tape on the threads so anything leaking past the seal meets more resistance before leaking out.)

The leak is now more solved but not solved. I think the return line may have something wrong with it that I cannot see. Or the taper on the Delphi regulator I have is a little rough. Anyway, the fuel smell is significantly reduced. If anyone has a lead on an OHV return line please let me know. They seem to be obsolete and not made aftermarket.

 

[lil_Blue_Ford]

I wanted to update the thread with some new findings. I got a really good look at the problem when I had the engine out. It seems that the o-ring is not the issue. Its the bubble-and-taper joint on the fuel return. I had much better leverage from this angle and I really cranked it down as tight as I was brave.

Spoiler

(I know this is wrong for many reasons, but I put some ptfe tape on the threads so anything leaking past the seal meets more resistance before leaking out.)

The leak is now more solved but not solved. I think the return line may have something wrong with it that I cannot see. Or the taper on the Delphi regulator I have is a little rough. Anyway, the fuel smell is significantly reduced. If anyone has a lead on an OHV return line please let me know. They seem to be obsolete and not made aftermarket.

I’ve wondered for awhile if it’s all just 37* seat and AN sized. If it was, you could use JIC or AN fittings