Question: leak near fuel regulator

[C4ME]

I noticed my car running oddly. Stumbling slightly when I first found the leak. Leaking enough that I cannot drive the car. Is it possible to have a pressure problem causing the leak? I have not measured the fuel pressure at the rail. The leak seems to be intermintant as I ran the car around the neighborhood with no issue for an 20 mins. Got on the the throttle a few times to see how it ran (purely experimental). Everything fine. Now tonight, I let the car idol in the garage and had the leak again. Never got to temp fully. I cannot exactly pin-point the spot of the leak as well. Looks wet around the regulator on the passenger side rail top. Any ideas would be great. Thinking of replacing the inj. o-rings and rail o-rings as well...and may be the regulator. Would rather know the answer to the pressure question first.

on a side note, I know it is sacrilege, but am watching a James Bond flic and just love the Aston Martin DB5...not as much as vettes, but wow!

 

[boomdriver]

I noticed my car running oddly. Stumbling slightly when I first found the leak. Leaking enough that I cannot drive the car. Is it possible to have a pressure problem causing the leak? I have not measured the fuel pressure at the rail. The leak seems to be intermintant as I ran the car around the neighborhood with no issue for an 20 mins. Got on the the throttle a few times to see how it ran (purely experimental). Everything fine. Now tonight, I let the car idol in the garage and had the leak again. Never got to temp fully. I cannot exactly pin-point the spot of the leak as well. Looks wet around the regulator on the passenger side rail top. Any ideas would be great. Thinking of replacing the inj. o-rings and rail o-rings as well...and may be the regulator. Would rather know the answer to the pressure question first.

on a side note, I know it is sacrilege, but am watching a James Bond flic and just love the Aston Martin DB5...not as much as vettes, but wow!

The leak could be internal and exiting thru the regulator cap. When the diaphram fails it sends too much fuel to the intake thru the vac hose, where it causes the engine to run rough & rich. Or, an O-ring fails on or near the regulator.A rail O-ring can be leaking or an injector o-ring. At that age,. they can ALL be leaking since they have been attacked by fuel cut with alcohol. The crossover tube is a favorite place for a leak to start.

If you;re planning on O-rings, spend another $250 at FIC, speak to Jon and get a new set of injectors. He might have a regulator kit as well, any parts store will be able to get one if he can't.

The key to success here is doing the work CLEAN. When you assemble the rails O-rings and install them, don;t allow things to twist,. & lube everything with vasoline and keep the dust/grit out and test for leaks as soon as the rail is bolted down and fuel lines connected. Purge the air out and simply power ON with the key and check pressure with the gauge. Allow it to hold that pressure for a while and if no leaks appear, finish the assembly.

 

[vetteboy86]

If the pressure regulator is defective, fuel could exit through the vacuum port on the regulator. This would also require an escape point meaning there is a vacuum leak on the regualtor vacuum feed.

 

[C4ME]

Looks like if may have found it...will disassemble to verify.

Thank you both! Tonight I believe I found the issue to be the passenger side of the regulator block and rail interface to be the leak. There was gas on top of the rail at this point. I will follow the sage advice.

Joe