Replacing injector seals

[IDigMy280]

Do you have to release the fuel pressure in order to replace the "O" ring seals for the fuel injectors?

Thanks!

[zbane]

YES. I suppose you don't have to, but it'll happen anyway, and will be very messy (not to mention unsafe).

[IDigMy280]

From what I've read, it doesn't sound like a really fun job either...?

[zbane]

releasing the pressure is not a hard thing to do at all. There is the FSM way, and there are other ways as well. I would imagine that you've probably come across several threads about just that.

[conedodger]

I have never found there to be too much pressure in the line. I think after all these years they just leak down their pressure...

[DatsunZsRule]

Did all mine about a year ago when I replaced all my injectors Make sure you put a little light weight oil on the 0 rings before you install them. I used 3-IN-ONE Oil on mine before installing

As for wheather or not you should depressurize the fuel system, Yes. If you don't you'll have a mess

[DatsunZsRule]

I have never found there to be too much pressure in the line. I think after all these years they just leak down their pressure...

There not suppose to "Leak down" If it does you got a problem like a leak somewhere in the system or a bad check valve. This applies to EFI 280Z's however. After seeing your signature, looks like you have a 240Z so your not going to have 36PSI of fuel pressure to worry about when disconnecting a fuel line

[IDigMy280]

thanks for the info fellas....I read the FSM, got one with the car but I'm not sure I understand all this soldering iron stuff??? Never disassembled any kind of fuel injection system before...

Can someone explain what the heck they are talking about? Also, if I'm gonna dig in this deep what else would you recommend I fix/replace/check while I'm pulling these injectors out..

Thanks, I've had the car less than two weeks and it's already coming along...

[sblake01]

The soldering iron is to heat the hose enough so it will come off of the injector easier. I never use that technique. Putting heat to something that has gasoline in it is not something I generally think about doing. I cut the hose just above the barb and cut the rest off with an exacto type blade. Be careful not to cut the injector or yourself.

conedodger, you haven't worked a lot with the EFI cars, have you?

[conedodger]

There not suppose to "Leak down" If it does you got a problem like a leak somewhere in the system or a bad check valve. This applies to EFI 280Z's however. After seeing your signature, looks like you have a 240Z so your not going to have 36PSI of fuel pressure to worry about when disconnecting a fuel line

I have actually had many Z cars and most were 280Z's. My point was that after 30 some odd years most of them leak down their pressure even though they are not supposed to. I have seldom seen any more than a bit of dribbling. The sign that this is the case in your EFI Z is hard hot starting. I had the injectors cleaned and balanced in the last 280Z I had and it did hold pressure. I knew this because I installed a gauge inline...

[IDigMy280]

The soldering iron is to heat the hose enough so it will come off of the injector easier. I never use that technique. Putting heat to something that has gasoline in it is not something I generally think about doing. I cut the hose just above the barb and cut the rest off with an exacto type blade. Be careful not to cut the injector or yourself.

conedodger, you haven't worked a lot with the EFI cars, have you?

So, cut and replace with new fuel line then?

The car idles about 400-500 RPM's too high and this is the only thing I can think of. I have used the FSM and checked most all of the other EFI components. I hear a distinctive hiss from that injector when I use a piece of hose to isolate the sound. It will also just stumble and die when idling sometimes. Even after as many as 10-15 minutes of idling beautifully. A little high, but idles nice..

Think this might be it Blake?

[GreenGraffix]

I just went down this road when i made my custom fuel rail and if you are replacing the old hose going directly to the injector it is a pain in the arse to get that hose off the bard especialy when it is old and dry rotted I spent 30 min or more just getting the old hose off the injectors. I had a vacauum leak by my injectors and replaced my seal and the sucking - hissing noise went away. I also bought all new hardware to screw all the injectors down with seeing how the philips heads were stripped out in some cases. I spent $2.40 for the metric bolts to fit them at lowes. New FI hose will be the most expensive part of the project.