Injector seals leaking?

[longrange223]

how do you test to see if your injector seals are leaking?

[gtspowerstroke]

About the only real test I know of is pressureizing the oil rail in the head. I've never done it but there is a way to put a fitting on the head and a pressure gauge and use a grease gun to pressurize it and see if it leaks down.

Tell us a little more about what makes you think you have some bad o-rings.

[longrange223]

mostly have been reading about poor fuel milage & low power til engine warms up,getting about 14mpg all around,straight 4" pipe no muffler & tymar intake setup,running a superchip on performance tune,seems to run well with maybe a little miss at idle,any suggestions?

[ryandamo]

is your engine loosing oil but not appearing to have any heavy leaks?

Also take your fuel filter out of the fuel bowl, if the fuel is black then most likely your rings are leaking.

[longrange223]

will have to check those things out,gives me something to look at,thx...r

[gtspowerstroke]

The fuel in the bowl getting dark is mainly just on the '94-'97 trucks because they have a flow through the heads design where the return fuel goes back out the heads and to the tank. On the SDs they have a dead head system so the fuel just stays in the heads until it get's used so it doesn't return to the bowl to get dark. If the middle o-rings are leaking it would be using oil. If the upper one is leaking it wouldn't though because it'd just be going back to the sump.

[longrange223]

then how do you know if they're leaking? what about the copper seals?

[gtspowerstroke]

If the copper seals are leaking typically you'll have a lot of white smoke at idle and if they are really bad it'll have a very loud knocking sound like WAY to much timing because it's dumping fuel in the cylender all the time. What happens is the copper fails and then the combustion gases gets into the lower chamber and melts the lower orange fuel seal. Then the fuel leaks into the cylender.