82 fuel leaking from dampener
07-20-2018, 12:19 PM
#1
Race Car
Thread Starter
82 fuel leaking from dampener
82
Car sat for a long time replaced most of the fuel system tank, pump, filter had lines ultrasonic cleaned and injectors rebuilt.
While doing a leak test the TB filled with gas I found the dampener leaking fuel at the vacuum port. The odd part is it is holding vacuum but then pressured fuelleaks out fast, any ideas besides just replacing it kind of goes against testing results.
Its odd the vacuum is holding about 15 steady.
Car sat for a long time replaced most of the fuel system tank, pump, filter had lines ultrasonic cleaned and injectors rebuilt.
While doing a leak test the TB filled with gas I found the dampener leaking fuel at the vacuum port. The odd part is it is holding vacuum but then pressured fuelleaks out fast, any ideas besides just replacing it kind of goes against testing results.
Its odd the vacuum is holding about 15 steady.
07-20-2018, 12:43 PM
#3
It's fine, just put a catch can close.
07-20-2018, 01:05 PM
#4
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
... And have the fire dept standing by anytime you run the fuel pump. What could go wrong?
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Vacuum testing the diaphragms offers a maximum of maybe 14 PSI delta across them. The fuel pump easily doubles that. The parts are still less than 40 years old, yet seem to suffer from age-related degeneration. We need to look at these pressure dampers and regulators as we do fuel hoses -- aging rubber things that keep the fuel from pouring out and causing engine-bay fires. Beyond the obvious, there's slao the issue of oil dilution as the fuel in the throttle ends up in the oil sump via the vapor recovery system. Those hose are now weakened by fuel exposure, plus the fuel condenses and weakens the oil in the sump.
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Things to think about:
Does your car seem to have issues restarting especially hot? Seem like it's vapor locked and/or flooded? Leaking dampers and FPR may well be the cause, but not necessarily the way we have been thinking, with the FPR bleeding back into the tank.. Sniff the vacuum limes for fuel after shutdown. Better, jumper the fuel pump relay for a short while, check for obvious leaks as well as fuel in the vacuum system. Doing this cold offers a better chance of finding liquid in the vacuum lines. Might be a part of an at-least-annual inspection as the cars age.
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Vacuum testing the diaphragms offers a maximum of maybe 14 PSI delta across them. The fuel pump easily doubles that. The parts are still less than 40 years old, yet seem to suffer from age-related degeneration. We need to look at these pressure dampers and regulators as we do fuel hoses -- aging rubber things that keep the fuel from pouring out and causing engine-bay fires. Beyond the obvious, there's slao the issue of oil dilution as the fuel in the throttle ends up in the oil sump via the vapor recovery system. Those hose are now weakened by fuel exposure, plus the fuel condenses and weakens the oil in the sump.
-----
Things to think about:
Does your car seem to have issues restarting especially hot? Seem like it's vapor locked and/or flooded? Leaking dampers and FPR may well be the cause, but not necessarily the way we have been thinking, with the FPR bleeding back into the tank.. Sniff the vacuum limes for fuel after shutdown. Better, jumper the fuel pump relay for a short while, check for obvious leaks as well as fuel in the vacuum system. Doing this cold offers a better chance of finding liquid in the vacuum lines. Might be a part of an at-least-annual inspection as the cars age.
07-20-2018, 01:34 PM
#5
Former Vendor
Most likely, the other damper/regulator are the same age and have been subjected to the same bad fuel.
Replace all of them.
Replace all of them.