[TTAZ Tech]      

Injector Installation

Background:
Please read this entire tech section before even considering starting. There are a lot of detailed separate steps that need to be followed. If you don't pay attention to the details and rush things, you could end up with a fuel leak, water leak, vacuum leak, or electrical short. It wouldn't be fun taking the upper manifold off again to fix a leak. I took my time and none of this happened.

Also, I seriously suggest investing in a factory service manual. You may want to use the service manual as a reference for the vacuum line routing. However, the service manual doesn't tell you step by step on how to replace injectors. Good luck and e-mail me if you have any questions.

Timing:
When you have an injector that needs to be replaced or are upgrading to larger injectors for performance.

Parts:
    new injector(s)
    re-programmed ECU or aftermarket controller (only for larger injectors)
    stickers or paper for marking things (paper strips, Scotch tape, pen)
    shop towels / rags
    zip ties
    Liquid Wrench or other bolt-loosening spray
    petroleum jelly
    high-temp silicone adhesive
    teflon tape
    replacement hoses (see section below)
    new injector connectors (if you choose to replace them):
      Nissan P/N: 24079-25P26 (2 required)
    new upper injector o-rings:
      02/89 - 07/90 NA: Nissan P/N: 16618-10V05 (6 required)
      07/90 - 09/91 NA: Nissan P/N: 16618-10V05 (3 required)
      09/91 - 09/93 NA: Nissan P/N: 16618-10V05 (6 required)
      09/93 and newer NA: Nissan P/N: 16618-53J00 (6 required)
      07/89 - 07/90 TT: Nissan P/N: 16618-10V05 (6 required)
      07/90 - 07/95 TT: Nissan P/N: 16618-10V05 (3 required)
      07/95 and newer TT: Nissan P/N: 16618-53J00 (6 required)
    new lower injector o-rings:
      02/89 - 07/90 NA: Nissan P/N: 16618-10V00 (6 required)
      07/90 - 09/91 NA: Nissan P/N: 16618-10V00 (3 required)
      09/91 - 07/92 NA: Nissan P/N: 16618-10V00 (6 required)
      07/92 - 09/93 NA: Nissan P/N: 16618-53J00 (6 required)
      09/93 and newer NA: Nissan P/N: 16618-10V05 (6 required)
      07/89 - 07/90 TT: Nissan P/N: 16618-10V00 (6 required)
      07/90 - 07/95 TT: Nissan P/N: 16618-10V00 (3 required)
      07/95 and newer TT: Nissan P/N: 16618-10V05 (6 required)
    new intake manifold gasket:
      02/89 - 01/90 NA: Nissan P/N: 14033-30P01 (1 required)
      01/90 - 07/95 NA: Nissan P/N: 14033-30P02 (1 required)
      07/95 and newer NA: Nissan P/N: 14033-30P03 (1 required)
      07/89 - 12/89 TT: Nissan P/N: 14033-30P01 (1 required)
      12/89 - 07/95 TT: Nissan P/N: 14033-30P02 (1 required)
      07/95 and newer TT: Nissan P/N: 14033-30P03 (1 required)
    new throttle body gaskets:
      02/89 - 04/90 NA: Nissan P/N: 16175-30P00 (2 required)
      04/90 - 07/95 NA: Nissan P/N: 16175-30P70 (2 required)
      07/89 - 04/90 TT: Nissan P/N: 16175-30P00 (2 required)
      04/90 - 07/95 TT: Nissan P/N: 16175-30P70 (2 required)

Installation:

Part 1: Removing the Upper Intake Manifold (Steps #1 to 23)

1. Remove all of the spark plug coils and number all of the coil connectors. (1.) I used paper strips, Scotch tape and a pen.

2. Remove the balance tube.

3. Remove the battery.

4. Remove the master brake cylinder. Make sure you use a 10mm tubing wrench to remove the hydraulic lines, and have plenty of rags ready to catch the fluid. There are four nuts that secure it to the brake booster.

5. Remove the intake boost hoses going to the throttle bodies and the boost hoses going to the intercoolers.

6. Remove and number all of the injector connectors. (1.)

7. Remove all visible vacuum hoses attached to the intake manifold. This is the hardest part. You really have to look and find these.

8. Remove the throttle cable and the cruise control cable.

9. Remove the throttle position sensor located on the driver's side throttle body.

10. Remove the passenger's side EGR tube. (2.) This is located right underneath the manifold after the throttle body. There are two 10mm bolts holding it in.

11. Remove the water lines and vacuum hoses going to the throttle bodies. (3.) Each throttle body has two water lines going to it. This was made for pre-heating the throttle bodies for Z cars located in the freezing climates. For Zs not living in this type of climate it can be bypassed during re-assembly (see the section below on doing this). It may be difficult to remove these lines with pliers. I had to resort to cutting them off.

12. Remove both throttle bodies. Removing the throttle bodies provides easier access to vacuum lines, water lines, and EGR lines. Requires metric allen wrench set. There are four holding the throttle bodies.

13. Remove the driver's side EGR tube. (4.) This uses two 10mm bolts located under the manifold after the throttle bodies. I found it easier to use a 10mm crow's foot because of the limited space for accessing it.

14. Remove the wire connectors on the fuel regulator and the dampener near the firewall.

15. Remove the PCV hoses located on the driver's and passenger's side of the engine. (5.) Each hose goes from the valve cover to the underside of the manifold. In some cases the driver's side hose may be as hard as a rock and should be cut off with a small hacksaw.

16. Remove the metal fuel line and hoses located on top of the intake manifold. Have rags ready to capture any fuel.

17. Remove all of the mounting bolts securing the intake manifold. These are bolts located in the center. Make sure you get all of them. There are some hidden near the back.

18. Pull the wiring harness out of the way. Use zip ties to hold the harness away.

19. If you have already removed the throttle bodies, you can use a pry bar or pipe to stick inside each of the throttle openings of the manifold to use as leverage to lift off. By trying to lift off the manifold, anything that you missed removing will be obvious as you try to lift it.

20. Underneath the manifold on each side are water tubes and water rubber lines. While lifting the manifold off you will see these lines. (3.) These lines will keep the manifold from being removed. You can cut or remove the rubber water lines.

21. Once the upper intake manifold is off, cover the six port openings on the lower intake manifold with rags to prevent foreign objects from falling in. (6.)

22. After removing the manifold, you will see the fuel rails attached to the lower intake manifold. (7.,8.) Remove the fuel rail from the lower intake manifold. Be careful not to lose the 12 plastic pieces that go above and below the mounting screws for the fuel rail.

23. With the fuel rail out of the engine bay, remove each injector from the fuel rail. (7.,9.) You have to remove the two screws holding the aluminum injector holder on top of each injector; they can be real tight. Make sure to use plenty of Liquid Wrench and a good Phillips screwdriver, otherwise you can strip the top of the screw. Removing the injectors requires prying and patience if you want to take them out without damaging them.

Optional: Replacing the PCV Valves (2.,10.)

With the upper manifold off, it is a good time to replace the PCV valves. You can buy PCV valves at any major auto parts store. They only cost $2-$3 each and you need two. Make sure you get the PCV valves made for your Z, whether TT or NA, and not universal ones. The PCV valves have to withstand boost (TT model), therefore they are made of heavy duty steel. Be sure to use teflon tape to seal the threads when you install the new PCV valves.

Optional: Re-Routing the Throttle Body Water Lines

This can be done before the upper intake manifold is attached. The water lines for the throttle bodies can be completely bypassed for those of you not living in freezing-type climates. The back of the engine has a metal water line with two output tubes which correspond to what side of the engine they goto. (14.) Route the water lines from each of these two tubes directly to the turbo water lines on both sides of the engine. (15.) I would buy about 6 ft. of hose to get this done for both sides; you can cut the hose to right length. Any left over hose you can use on other parts the engine.

Note: Buying Hoses

Go to your local auto parts store (NAPA, Pep Boys, Checker/Shucks/Kragen, etc.) and get all the replacement hoses you need. Take samples with you to match the sizes. You want to buy water line, vacuum lines, and fuel injections fuel lines. The passenger's side PCV hose has to be purchased from the dealer because of the special bend it has. The driver's side PCV hose is just a straight rubber hose which you can buy at the auto parts store.

Part 2: Installing the New Injectors to the Fuel Rail (Steps #24 to 26)

When installing new injectors, whether they are stock or upgraded, make sure you use new o-rings. The injector o-rings are cheaper to order from Steve @ Courtesy Nissan. Installing the injectors to the fuel rail is easier and safer when the rail is off the vehicle. On a clean work bench, install all the new o-rings on the injectors. There are two o-rings per injector.

24. Using a petroleum jelly (i.e. Vaseline), apply the jelly liberally on all of the o-rings and the inside of the injector housing on the fuel rail to provide lubrication for pressing in the injectors. Don't worry about getting jelly on the wire mesh part of the injectors because it will dissolve instantly when the gasoline hits it.

25. Install each injector in the fuel rail by initially pressing them in most of the way by hand, and then attaching the injector holder on top with the two screws. Note: make sure the injector connector on top is facing the proper direction. Alternate between the two screws a few turns each to make sure the injector goes down evenly until fully seated inside the rail.

26. Install the fuel rail on to the lower intake manifold. There are six o-rings that seal the fuel rail to the lower intake manifold. Make sure you use new o-rings and that they are in place on the lower intake manifold when placing the fuel rail on the lower intake manifold. There are six screws that secure the fuel rail in place. Each screw has two small plastic pieces that sandwich the fuel rail.

Optional: Replacing Injector Connectors (8.,11.)

Please read this entire section before starting. The order of putting the manifold on and replacing the injector harnesses is important. If you are installing new injectors in your Z, now is a good time to replace the injector connectors; chances are that your original connectors are corroded. Purchase the harness connectors from Steve @ Courtesy Nissan. Part number is 24079-25P26 and you'll need two of these. They cost $18.22 each. You splice and solder the connectors to the main harness. The harness kit from Courtesy belongs to another Nissan car (I am assuming the Maxima), but they use the same injector connectors.

Each new harness has three connectors; each connector has two wires - red and green. Cut the connectors from the new harness, leaving yourself about 6 inches of wires on the connectors. Save the black insulating rubber tubes. These will be placed over the wires before splicing.

With the upper intake manifold off and the fuel rail installed on the lower manifold, attach all the connectors to the new injectors (see the above section for installing the injectors on to the fuel rail). Install the holding clip. Be careful you don't lose these while attaching the clips.

When you install the upper manifold back on the engine (see section below), make sure the injector wires are sticking up between the appropriate intake runners. Place the black insulating tube over the wires once the connector is installed on the injectors. After the manifold is bolted in place, you can splice and solder the main harness onto the new injector connector wires (Step 7 of below). If you don't know how to splice and solder have a friend with experience do this or show you. You want solid and clean connections. The engine wiring harness uses white/black color wires as the negative (or ground) for all six injectors and six different colored wires for the positive polarity. Splice and solder the black/white (negative polarity) wire onto the green wire of the new connector. The red wire of the new connector is soldered/spliced to the other colored wire of the of harness. When you are done splicing and soldering, use heat shrink and hi-temp electrical tape to insulate the connections.

Part 4: Re-attaching the Manifold (Steps #27 to 36)

Assuming you have bypassed the water lines directly to the turbo water lines, reinstalled the fuel rail to the lower intake manifold, attached new injector connectors without splicing to the main harness, replaced the fuel lines, vacuum hoses, water lines hoses, PCV hoses, and PCV valves, you can now re-attach the manifold.

27. Put a new intake manifold gasket on the lower intake manifold. (8.) Make sure the bolt holes line up. I used high temperature red silicone adhesive on both sides of the gasket. This will prevent any vacuum leaks. Apply the silicone to both sides of the gasket and to the bare aluminum bottom of the upper intake manifold, and let the silicone sit for 20 minutes.

28. Install the upper intake manifold. (12.,4.) When putting the manifold back on, attach the PCV hoses to the manifold first. Insert the EGR tubes into the bottom of the manifold, otherwise the manifold won't be fully seated. I used petroleum jelly to coat the inside of the hoses; the hoses slipped right on. Make sure the manifold is seated down all the way on to the lower intake manifold.

29. Once the manifold is in place, attach the PCV hose clamps on. (5.) The driver's side goes directly to the valve cover. The passenger's side has a metal tube which the hose goes on to. I had to buy a new PCV hose from the dealer for the passenger side, since it has special bends in it.

30. With the PCV hoses secure, install the manifold bolts. Torque the manifold bolts to 16-20 ft.lbs. Use a criss-cross fashion when torquing them down.

31. Secure the EGR tubes with two 10mm bolts on each side (remember the driver's side requires the 10mm crow foot). (4.)

32. Install the throttle bodies on both sides. (13.) Remember to use a new gasket with the throttle bodies and apply the same type of silicone used for the manifold gasket.

33. Splice and solder the new injector connectors to the harness (see the above section). If you're using the existing connectors, reattach them to the appropriately numbered injector.

34. Install the throttle cables and the cruise control cable.

35. Install the top metal fuel line piece on top of the manifold. Make sure you tighten the hose clamps sufficiently to prevent any fuel leaks.

36. Install the remaining vacuum lines, electrical connectors, coil packs, master brake cylinder, ecu, battery, etc.

Mike Hageali 		1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
10. 
11. 
12. 
13. 
14. 
15.