Fuel Damper
08-02-2004, 07:19 PM
#2
Three Wheelin'
The purpose of the fuel pressure damper is to eliminate fuel pressure pulsations. As the injectors are fired, the pressure in the fuel rail drops, and then rises as the injector closes. Since fluctuations in fuel pressure can cause changes in the fuel/air mixture, a pressure damper is necessary.
08-02-2004, 08:29 PM
#4
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Drive the car for a few minutes (warm it up). Then pull out the oil dipstick, wipe it on your fingers and smell it. If you smell fuel, its bad.
08-02-2004, 09:55 PM
#5
Three Wheelin'
I can think of a couple of tests, and smelling the oil ain't one of 'em, (sorry hosrom).
1. With the engine off, disconnect the vacuum line to the damper and apply a vacuum to the damper (a MityVac is perfect for this.). If the damper holds vacuum, chances are it's good.
2. With the engine off, connect a pressure gage to the fuel rail, start the engine, and watch the gage. If the gage "flutters", chances are the damper is not working properly. Next, disconnect and plug the vacuum line. If the fluttering doesn't change (it should get more pronounced), then the damper is bad.
3. If you don't have a fuel pressure gage and/or a MityVac, you can use the "feel" method: Start the engine and feel the soft line at the damper end of the fuel rail. With your other hand, disconnect and plug the damper vacuum line. If the vibrations in the soft line do not change, the damper is bad.
Fuel in the oil can be an incidation of an overly rich mixture, worn rings, or a leaking injector (fuel from an injector leaking after engine shut down gets past intake valve and washes down the cylinder wall and ends up in the crank case.). One of these can be traced to a bad fuel pressure regulator, but not to a bad fuel pressure damper.
1. With the engine off, disconnect the vacuum line to the damper and apply a vacuum to the damper (a MityVac is perfect for this.). If the damper holds vacuum, chances are it's good.
2. With the engine off, connect a pressure gage to the fuel rail, start the engine, and watch the gage. If the gage "flutters", chances are the damper is not working properly. Next, disconnect and plug the vacuum line. If the fluttering doesn't change (it should get more pronounced), then the damper is bad.
3. If you don't have a fuel pressure gage and/or a MityVac, you can use the "feel" method: Start the engine and feel the soft line at the damper end of the fuel rail. With your other hand, disconnect and plug the damper vacuum line. If the vibrations in the soft line do not change, the damper is bad.
Fuel in the oil can be an incidation of an overly rich mixture, worn rings, or a leaking injector (fuel from an injector leaking after engine shut down gets past intake valve and washes down the cylinder wall and ends up in the crank case.). One of these can be traced to a bad fuel pressure regulator, but not to a bad fuel pressure damper.
08-02-2004, 10:30 PM
#7
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I had a bad FPR and replaced it with no difference in fuel smell in the oil.
I changed the FPD and the smell was gone.
I contacted a few people to comfirm this (since i have serviced injectors from Bosch Service Centre) and the problem was with the FPD.
I am not saying that the FPD is the ONLY problem to get fuel in the oil. But it is ONE of the issues which does.
I changed the FPD and the smell was gone.
I contacted a few people to comfirm this (since i have serviced injectors from Bosch Service Centre) and the problem was with the FPD.
I am not saying that the FPD is the ONLY problem to get fuel in the oil. But it is ONE of the issues which does.
