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  • Fuel injector removal/reinstallation

    I've read over the FSM and Haynes procedures for fuel injector removal, and they both leave a bit to be desired after getting the fuel rail, injectors and pressure regulator off the engine. I know I can "learn by doing" but was hoping someone knew a good site that has illustrations in full technicolor showing the fuel tube removal and reassembly. I even searched for vids, all I found was Z32 stuff on YouTube...

    Searched the forums (fora?) and couldn't find much that was useful. I'm presently looking to remove and assess each injector for functionality and cleanliness. Will probably try to clean up and re-use what I've got for now, just for kicks and giggles. Don't have any intentions of doing a NA2T on this car, so have no need to go bigger. Don't know whether the injector campaign was completed, but believe it was based on the yellow tape on the injector harness. Will call the local dealer to see if they can look it up and confirm. If they have, and I can clean 'em up, I'd like to keep them and spend my money on other stuff.

    Thanks in advance for any suggestions.
    '86 NA - original owner (1986-93) and final owner (2005-present)

    My build thread: http://z31performance.com/showthread...-Got-mine-back


  • #2
    Nissan sells new fuel injectors with a short section of hose already crimped on, this is because the hose/clamp system isn't designed to be serviceable... just cut the hoses where they bend with an exacto knife, then with some gentleness cut up and down to reveal the barbs

    It will be a pain in the ass to remove them, and you may want to pre-cut new sections of hose to exact matching lengths for replacing them later

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    • #3
      That's the part I'm most uncomfortable with - would like some better pictures of what that looks like before I go slicin' (or melting per the FSM - what's with that anyway?). Really not into the idea of getting new ones if I can clean up the gunk that I suspect is fouling the ones I've got. Did the fuel tank cleaning, tried flushing the fuel lines but there must be stuff in the injectors too. Have seen some demos of injector cleaning that I think would fix it, but I need a little more info before I start in on it. Or maybe I just dive in... if someone has a picture of the injector without the fuel line on it, that would probably be enough.
      '86 NA - original owner (1986-93) and final owner (2005-present)

      My build thread: http://z31performance.com/showthread...-Got-mine-back

      Comment


      • #4
        The end of the injector that goes into the line is just a barbed fitting, nothing special or hard to deal with. When you reassemble them all, you just need regular fuel injection hose (make sure it's rated for fuel injection systems, as regular fuel line is not rated for the higher pressures). You just shove the barbed end into the hose, then put a fuel line clamp on it and you're done. It's pretty simple.

        Here's an injector picture...
        Prius... because Pretentious wouldn't fit across the back of the car...

        Cheap, Fast, Reliable - pick any two

        My 1986 Turbo Build

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        • #5
          Thanks, man. Appreciate the picture. I just pulled the upper intake tonight, and based on how hard that was to just get at them, I'm thinking I may re-evaluate the plan to "clean and re-use"... don't know how old they are, but I'm guessing at least 15 years if they were done under the service program. I don't want to have to do this again, so I'll probably just put new ones on it. Haven't priced it out yet, so we'll see.
          '86 NA - original owner (1986-93) and final owner (2005-present)

          My build thread: http://z31performance.com/showthread...-Got-mine-back

          Comment


          • #6
            It's not that expensive to have them serviced if you aren't planning to upgrade. Witchhunter will do them for $22 per injector. To take them out, you just want to take the little bolt out of each injector, disconnect the fuel lines to the fuel rails, then pull the whole rail and injector assembly. Once it's out you can work on removing each injector from the rail.

            http://witchhunter.com/injectorserv1.php
            Prius... because Pretentious wouldn't fit across the back of the car...

            Cheap, Fast, Reliable - pick any two

            My 1986 Turbo Build

            Comment


            • #7
              Wow, that looks like a heckuva good deal... are they here on Z31P? On a Jeep forum I belong to, vendors have their own account and offer deals to forum members, etc. Not trying to get a break on cost, really just wondered what their presence and reputation was here, figured that's the acid test.
              '86 NA - original owner (1986-93) and final owner (2005-present)

              My build thread: http://z31performance.com/showthread...-Got-mine-back

              Comment


              • #8
                Not that I know of. They don't deal in any specific car market. Fuel injectors are fuel injectors, they work with all of them as far as I know. If you google "witchhunter performance" the first 3 forum threads that show up are good reviews from a BMW forum, a Porsche forum, and NASIOC (Subaru forum), so I would say they have a pretty good reputation.
                Prius... because Pretentious wouldn't fit across the back of the car...

                Cheap, Fast, Reliable - pick any two

                My 1986 Turbo Build

                Comment


                • #9
                  Started injector removal - is this a problem?

                  Got the first two injectors off the fuel rail tonight, and wanted to ask a question for those who have more experience.

                  Went with the X-acto knife to get the hose off the barbs. Left a small score mark on the hose barb on both injectors. I can use some 1500 wet-dry to polish them out, but just wanted to make sure it wasn't going to create some other problem. Didn't see a mark on the fuel rail barbs, but wouldn't be surprised to find something similar. Here are a few pictures to illustrate.

                  The #1 injector fully disassembled



                  Up-close of the hose barb



                  Hose barb on the #2 injector - same thing



                  These are basically just light scratches in the surface, but I've read comments about making sure you don't damage anything taking them apart, so I just wanted to see if I'm over-working it.

                  Injector tips look pretty fouled... here's an example. This is probably the worst one... of course, there's no telling what the insides of these things look like.



                  Going to finish pulling the rest off of the rail tomorrow night, then package and ship off to WitchHunter first thing next week.

                  Thoughts about the score marks and anything else would be appreciated...
                  '86 NA - original owner (1986-93) and final owner (2005-present)

                  My build thread: http://z31performance.com/showthread...-Got-mine-back

                  Comment


                  • #10
                    Gently sand away the ridges from your scoring... next time cut sideways, almost like you're filleting a fish, once you've peeled away enough of the hose, it will be soft enough to twist and wiggle off, with only minor nipping away at the cords

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                    • #11
                      Good advice on technique...thanks. After the first two, I realized I needed to call a timeout and seek professional advice.
                      '86 NA - original owner (1986-93) and final owner (2005-present)

                      My build thread: http://z31performance.com/showthread...-Got-mine-back

                      Comment


                      • #12
                        Finished pulling the injectors and got them shipped off to WitchHunter today. The filet method turned out worse for me on the first one I tried that way...





                        I was able to get most of the roughness off with wet-dry sandpaper... then went back to the other method.
                        '86 NA - original owner (1986-93) and final owner (2005-present)

                        My build thread: http://z31performance.com/showthread...-Got-mine-back

                        Comment


                        • #13
                          Update on reinstallation

                          Have finally gotten back to the fuel injectors and reinstalled them. Pressurized the system and didn't see any leaks, but not ready to run the car yet so we'll have to wait to see whether they stay tight. Used new fuel injection hose with the old "umbrella" fitting covers... cut the hoses to 40mm length based on something I remember reading (but cannot find now). That's how long the ones I pulled off were.





                          Hoping to finish putting the engine back together in the next month so I can crank it and see how these do.
                          '86 NA - original owner (1986-93) and final owner (2005-present)

                          My build thread: http://z31performance.com/showthread...-Got-mine-back

                          Comment


                          • #14
                            Are you certain that fuel line says for fuel injection, cause I thought all of them had a layer of blue inside.

                            So why did you send out your injectors in the first place? Did they tell you the before and after results? And what was the price?
                            My Build Thread

                            Comment


                            • #15
                              Yes, this fuel line is rated for fuel injection. I don't know about the blue layer you speak of, because the hose I bought for inside the gas tank (rated for immersion in fuel) didn't have that either. There may only be one manufacturer who does that...just to distinguish themselves from others.

                              I sent the injectors out because my tank was full of crap and I was afraid some of it had gotten past the filter or similar stuff had formed in the line. The car sat for many months and after replacing the fuel pump I still couldn't get it to run well. I was tearing down the motor for a timing belt change anyway, so it wasn't too much money for the peace of mind. They did send me a test sheet of the before/after flow results. Surprisingly, there wasn't a significant deficit on any of them before being serviced. They did improve after servicing. I forget the pricing but it is around $200. Their website lists all the pricing.
                              '86 NA - original owner (1986-93) and final owner (2005-present)

                              My build thread: http://z31performance.com/showthread...-Got-mine-back

                              Comment

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