Fuel system depressurizing
M330CSi
05-26-2006, 11:25 AM
And while I have the back end lifted and wheels off, I was thinking of replacing the fuel filter. But of course the fuel lines need to be depressurized. Haynes sez that this can be done by disconnecting the fuel pump at the tank and that the tank may need to be lowered to do this (yeah, right! :disappoin The directions for lowereing the fuel tank say "first, depressurize the fuel system as described earlier"!). It also says that it can be done by attaching a fuel bleeder to the Schrader valve on the fuel rail. Is the fuel rail under the intake plenum? Can this be done without removing anything else? Where is this damn Schrader valve?
Is there a real world way of doing this? I've suspected that removing the fuel pump fuse might have a similar effect to disconnecting the pump- but Haynes doesn't say anything about it. What they do say is that if the system isn't depressurized by one of the above ways, there's the risk of getting a face full of fuel stream, and I'm pretty keen to avoid this.
Anyone done this?? I though changing the fuel filter was supposed to be simple! (OK, I though the same thing about the brakes....)
Is there a real world way of doing this? I've suspected that removing the fuel pump fuse might have a similar effect to disconnecting the pump- but Haynes doesn't say anything about it. What they do say is that if the system isn't depressurized by one of the above ways, there's the risk of getting a face full of fuel stream, and I'm pretty keen to avoid this.
Anyone done this?? I though changing the fuel filter was supposed to be simple! (OK, I though the same thing about the brakes....)
xeroinfinity
05-26-2006, 04:53 PM
Haynes isnt a very bright crayon :lol:
Pulling the Feul pump fuse is the easiest, just pull it and start the car and let it run till it dies and the pressure should be off.
If you hav a V6, the schrader valve is on the end of the fuel rails. It should hav a metal cap covering it. under the cap it looks like a bike air valve. THey do sell or rent the tool at parts stores that offer that service.
Most 4cly's dont hav a schrader valve. Pulling the FP fuse should be sufficient.
Once thats done it is easy.
Two wrenches for the nut(s) on the fuel filters one end, and I'm not sure on your year, but it should squeeze the other end to release the cheap connector.
More old rags come in handy here too, just because thiers no pressure, doesnt mean fuels still not in the line/filter, so watch your EYES !
That'll end your work in a hurry! :eek:
Pulling the Feul pump fuse is the easiest, just pull it and start the car and let it run till it dies and the pressure should be off.
If you hav a V6, the schrader valve is on the end of the fuel rails. It should hav a metal cap covering it. under the cap it looks like a bike air valve. THey do sell or rent the tool at parts stores that offer that service.
Most 4cly's dont hav a schrader valve. Pulling the FP fuse should be sufficient.
Once thats done it is easy.
Two wrenches for the nut(s) on the fuel filters one end, and I'm not sure on your year, but it should squeeze the other end to release the cheap connector.
More old rags come in handy here too, just because thiers no pressure, doesnt mean fuels still not in the line/filter, so watch your EYES !
That'll end your work in a hurry! :eek:
M330CSi
05-30-2006, 11:25 AM
Thanks for your rsponse! I'm making progess now. The fuel pump fuse idea didn't work. The fuel pump is on the same fuse as the fuel injectors. If I start the engine and pull the fuse, the engine dies instantly, I suspect because of the dead injectors and not because of a lack of pressure in the fuel line.
But the shraeder valve is where you said, on the left side of the engine just under the intake plenum. Now, time to see if I can beg, borrow or steal a fuel pressure gauge!
But the shraeder valve is where you said, on the left side of the engine just under the intake plenum. Now, time to see if I can beg, borrow or steal a fuel pressure gauge!
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