Tools for Machining Fuel Rail 1/8" NPT tap + clearance drill 12mm x 1.25 tap + clearance drill 9/32" or 5/16" diameter 16" long drill for boring out rail countersink Basic Tools 1/4 or 3/8 metric sockets, 10mm, 12mm in particular, extensions 17mm socket for large banjo bolts 6mm 1/4 or 3/8 drive allen key for EGR pipe T-20 Torx for throttle body medium adjustable wrench for EGR pipe (19mm?) pliers for water hose clamps screwdriver for hose clamps standard wrenches for Earl's fittings (7/16, 1/2, 11/16, 3/4) metric wrenches for various bolts (12mm for cold start banjo) a 32 tpi hacksaw or cutoff wheel for cutting hoses solvent and compressed air for cleaning hoses soft vise jaws (aluminum) for assembling fittings teflon tape or Loctite PST antiseize Plumbing Parts fuel rail ($135 new, $100 wholesale, free if you use the old one) crush washers and o-rings, see text wire ties or some way to keep hoses in place spiral wrap, rubber tubes from old fuel lines, etc. 4mm vacumn hose for the fuel pressure regulator Earl's Parts 1 925106 -6 AN TEE 2 991945 12mm x 1.25 to -6 adapters 3 300106 Auto-Fit -6 hose end 1 849091 Swivel-Seal 90 degree -6 to 12mm x 1.25 adapter 1 1/8" NPT to -3 adapter, see text 2 593202 1/8" NPT plug, internal wrenching 2 900x04 1/2" ID Econ-O-Fit or regular hose clamps 300006 -5 Auto-Flex braided hose for fuel return 300006 -6 Auto-Flex braided hose for fuel supply, rail 600003 -3 Speed-Flex teflon hose for cold-start injector 1 601503 90 degree -3 banjo fitting in steel (601533 in Al) 1 612103 120 degree adjustable -3 fitting, see text Toyota Parts 8 23291-75010 insulators for injectors 4 23845-88380 insulators for fuel rail 4 90301-14006 small injector o-rings 4 90301-17007 big injector o-rings Fuel Rail Machining With a new rail. . If you are reusing the old rail, you will have to skip down a bit. 1. Drill out the plug(s). (Old rails have one plug, new ones have two) Tap one or both sides for 1/8" NPT plugs and test fit the plugs to make sure they go in all the way as there is very little room on the sides of the rail in the car. Run the tap in about 1/2" or so. 2. Using a vise in a drill press, open the cold start injector hole (8mm x 1) up with the clearance drill for the 12mm x 1.25 tap and tap. Go slow, use the proper lubricant, and make sure you keep the drill centered and straight. 3. Drill out the center of the rail using the long drill. Use plenty of oil and go slow. Since the quill travel of most drill presses is inadequate, this should probably be done carefully with a hand drill. Ideal is a 9/32" drill, but 5/16" should work as well. 4. Chamfer the cold-start face slightly with the countersink (see text later) and clean up the rail. Make sure there are no chips or shavings that might end up in the injectors later. Degrease the rail and install the plug(s) using teflon tape or PST. If using PST, make SURE the rail is grease/solvent free and let it cure. 5. Tap the side of the AN TEE for 1/8" NPT. A smaller than normal clearance drill should be used (P or similar) as the tap can't be run in very far. A little bit of material will have to be removed from the inner wall to get sufficient thread engagement. This can be done carefully with a drill (make sure there is sufficent wall thickness) or an endmill. Install a straight or 90 degree 1/8" NPT to -3 fitting using pipe tape or PST and make sure it's tight. 6. Install one of the 12mm x 1.25 fittings using a 1/2" crush washer and -4 o-ring to keep it centered on the distributor side of the rail (some fittings came with crush washers, some may not. You could also use a 7/16" Stat-O-Seal). Loosely thread the AN TEE onto the fitting. On the timing belt side of the rail, install the 90 degree 12mm x 1.25 fitting in a similar manner. Determine what length of hose you will need to go from the 90 degree fitting (Swivel-Seal) to a straight Auto-Fit hose end so as to connect the 90 degree fitting to one end of the TEE (see pictures). It is possible to replace the 90 degree fitting with a straight adapter, and a 90 degree hose-end, but the hose won't be parallel to the rail.
7. The fuel rail is now more or less complete. The fuel feed will go into the AN TEE, the cold-start goes to the -3 fitting on the side of the TEE, and the fuel return comes from the regulator. Removal of Rail 1. Disconnect the ground side of the battery. Have a fire extinguisher handy, you'll be dumping a lot of fuel around. 2. Remove the throttle intake pipe, intake stay, throttle cable assembly, throttle body, EGR valve, EGR VSV and actuator, ISC air hose, ISC water hoses, and airbox assembly. Loosen the bolts holding the plastic wiring harness to the intake manifold. 3. Remove the banjo bolt from the fuel filter and drain as much of the fuel as possible into a handy container. Remove the fuel return line from the metal tube near the firewall and do the same. Remove the banjo bolts for the cold-start injector. 4. Remove the injector connectors, vacumn hoses, and the fuel line from the regulator. Remove the three bolts holding the rail in place and remove the rail gently. Remove the plate covering the injectors and the banjo bolt holding the line to the rail. Remove the fuel line brackets from the water inlet assembly. Installation of Rail and Hoses
1. Install new o-rings on the injectors (a light coat of gas helps ease them on), new insulators and install them in the rail. It may be necessary to bend or cut off the portions of hard vacumn line on the cover plate for clearance reasons. Install the fuel pressure regulator. Since it isn't possible to cut a proper o-ring groove in the material left from the cold-start injector bolt, cut the steel washer off the regulator, and use a 1/2" crush washer with a -4 Viton o-ring squeezed inside or you could do whatever you feel comfortable with, given that there is no standard solution. Orient the outlet of the fuel pressure regulator so that it will clear the closest injector harness with a hose and clamp on it. This means having the barbed outlet about 20 degrees off axis. 2. Loosen the black plastic wiring harness that sits on the intake manifold. The injector cover plate on the fuel rail actually sits underneath this making it extremely difficult to reinstall if you can't wiggle the black plastic holder around. Tighten the bolts and check to make sure the rail is seated properly. It is almost impossible to get the bolts to thread properly if it isn't. 3. Install the injector wiring harnesses so you can see what sort of clearance you have. You will notice that one of the water pipes for the throttle body is extremely close to your AN TEE. You can try to rotate it, but will most likely have to bend those water pipes up slightly with a wrench. 4. Fabricate a length of -6 line that will go from the fuel filter to the other side of the AN TEE. Also fabricate a length of -5 line (or some other 1/4" ID hose) that will go from the regulator to the fuel return hard line. Install these so that you can see how much room you have. Use a 12mm x 1.25 adapter on the fuel filter for attaching the -6 line. Use hose-clamps on the -5 line. 5. Test fit the throttle body. Most likely, it will not seat properly. The most likely cause is the ISC air intake tube hitting the fuel pressure regulator. Use the T-20 torx to loosen the set screw holding the tube and rotate it slightly. Note that the ISC valve limits how you can connect a banjo fitting to the cold-start injector. The 90 degree part specified above is just about the only part you can fit in there. 6. Fabricate a line for the cold-start injector using a banjo fitting on one side and a -3 fitting on the other. Currently, my rail has a 90 degree -3 to 1/8" NPT fitting with the -3 side pointing straight up, but many other configurations are possible. Check to see how the water and air hoses go when the throttle body is in place to see what works best. 7. Use rubber hose, hose wrap, Earl's Flame-Guard, etc. to provide heat and abrasion resistance. The stainless braid will cut through other hoses and fixtures, and sharp metal edges can damage aluminum fittings and the hoses. Run your lines in more or less the same place as the stock lines and fabricate a little bracket that bolts onto the water neck to hold the lines in place. 8. The cold start banjo bolt is 8mm x 1. Earl's does not make an adapter in this size or a banjo bolt. A 10mm banjo fitting seems to work OK. You can use a 5/16" Stat-O-Seal ONCE to seal this. 9. Once all the fittings are in place, and all of the hoses are tightened, connect the battery, short Fp and B+ in the check connector and turn the key to ON (don't START). This will start the fuel pump and should point out any leaks. If you can't hear or feel fuel moving through the lines, it isn't and you should check your SST.
10. Install the throttle body first to make sure it clears properly. If not, go back and fix it first. Reinstall the air and water hoses for the ISC (the car won't idle without the air hose) and make sure the appropriate clamps are in place. Reinstall the EGR pipes, valve, and VSV assembly. A little antiseize goes a long way here if you end up doing this more than once. Connect a new vacumn hose to the fuel pressure regulator. Install everything else in reverse order and make sure the car still works. A missing vacumn hose can cause all sorts of problems. Comments You can use Loctite PST or teflon tape for the NPT threads. Both seem to work fine when used as directed. The cold start is difficult due to the 8mm x 1 size which no one makes an adapter for. You can find 8mm banjo fittings,but they are hard to find. If you have the facilities, the best solution is to turn a standard -3 to 10mm fitting down to 8mm, or make aluminum crush washers that have an 8mm ID and an appropriate OD for the 10mm banjo fitting. A great variety of hoses can be used for the supply and return lines. Standard 1/4" ID fuel line would work for the fuel regulator return and Earl's Super Stock hose can be used for the fuel supply line with the appropriate -6 connectors. Given the cost of the Earl's hardware, good hose doesn't add much to the total expense. A tiny bit of antiseize on the threads of the AN fittings makes life a little bit easier when threading hoses on by hand. Use the appropriate wrenches on AN fittings to avoid overtorquing and scratching. Article prepared by Charles Grosjean
Back to Tech Page