With all the threads on injector swaps, I couldn't actually find a thread on how to actually do it. So, here we are.

First Thing you're going to want to do, is turn on the car and pop the hood. Open the fuse box in the bay and pull the Fuel Pump Relay. After the car stalls, crank the engine a few more seconds to ensure there's no fuel left in the rail. Now disconnect the negative terminal of the battery so there's a reduced risk of fuel vapor detonation and re-install the fuel pump relay. (Detonation is very unlikely. I spilled gas everywhere but I'm still here)

With me so far? Good. Here's were things get fun. Remove the entire upper intake manifold (there's a thread detailing how to do this with pictures [you need to scroll down] that really help out).

Now that you've gotten the pesky Upper Intake Manifold (UIM) out of the way, Remove the bolt holding the VDI actuator in place and swing it out of the way. It doesn't actually move that much, but its enough to get the fuel ail out.

Remove the hoses on the fuel rails with the blue and red lock rings. I put paper towels under the hoses to catch any gas that spilled out of the fuel rails. A lot came out.

After the hoses are out of the way, remove the two bolts holding the fuel rail in place.Wiggle the fuel rail out and pull the injectors out of the rail and Lower Intake Manifold (LIM). CAUTION: more gasoline may drain out of the fuel rail once the injectors are removed. There should be four yellow injectors attached to this rail (Only on the high power 6-port model). Disconnect the wires from the injectors. They can be kinda stuck so be persistent. Try gently wiggling the injector to break any built up grime keeping it in place. Once the injectors are free, take note and write down what wires went to these four injectors. Possibly mark them with colored tape to avoid confusion.

Time for the primary injectors. Tackle the two bolts holding the injector plate in place.

 

Once the bolts are out, flip the plate over and remove the primary injectors from the second fuel rail. Unplug them like the injectors before. Remove the fuel rail.

This is also a good time to remove any crud build up that you didn't notice before because there was an UIM blocking everything.

Now, if you're swapping injectors, you're probably doing this with FI in mind. Take two of your yellow injectors you just removed, and swap over the large rubber grommets from your red primary 1 injectors. I also had an injector o-ring repair kit, so I replaced all my old o-rings on the yellow injectors I was re-using. This is also the time to prep your new injectors you plan on installing. I installed the wire harnesses before hand to make my life easier.

 

Reinstall your new yellows prepped for your primary 1's by placing the injectors into the holes in the rotor housing. Attach the wires back into the primary injectors. Then take the small fuel rail and press it back over the injectors. Rebolt.

Use the same strategy for the four injectors on the long fuel rail. Place, wire, press, and bolt. Then simply re-attach the two tubes with the colored clips.

Bolt everything back up and re-attach the battery. Then, using your accessport or EMS management tools, slightly under scale the injectors (so it runs rich for safety purposes) and load the flash. Turn on the car and look for leaks. If no leaks are present after 5 minutes, you're good to go. Proceed to tune for for your new injectors!

If all this was a bit confusing, please use this to cross reference what I've outlined here: http://foxed.ca/rx7manual/2003mazdarx8/ The pages you need are headed under: Engine->Fuel System->Fuel Injector Removal/Installation

 

Nice writeup and good details. Thanks.

 

Thanks for the write up on this. Looks to be helpful for my future task. Quick questions:
1) There are 6 total injectors?
2) 1st Rail and 2nd Rail are same type of injector or different
3) Where do you suggest getting these?

Thanks again.

 

Nice detailed write up

 

If I'm swapping in new injectors, how do I figure out which grommets I need to buy?

 

Thank you for manual . Really help .

 

Just forewarning everyone that this online manual was a very early edition that has mistakes and is missing information. There are also variations between model years. If your serious about working on your RX8 then you need to go buy both the factory service manual and electrical manual for your specific model year.