Fuel injectors

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This is a quick write up for upgrading the Fuel Injectors to the RC PL8 550 Injectors for the Turbo upgrade. I used the write up by David R. Meyers which is in the Upgrade link on the LEC homepage [1] and as there is only one photo thought i`d post my photo`s here to help others in the future. So i`m just going to use Daves write up with my photo`s (hope he doesn`t mine)

Tools Needed:

12mm socket

14mm socket

Socket extension

Needle-nose pliers

Die pick (i used a thin flat screwdriver)

A long, standard screwdriver

T-26 Torx bit

RC Injectors can be bought direct from [2]

The RC PL8-550 (Bosh Style Top) compared to the stock injector

RC PL8-550 vs Stock Injector.jpg

RC Engineering's replacement for the stock injector is part number PL2-320 (Peak and Hold, bosch connector, 320 cc/min)

Before removing any parts, you must relive pressure form the fuel system. While the car is running, pull the fuse for the fuel pump (I tripped the Inertia switch). After it stalls, crank the engine for a few seconds to remove as much remaining fuel from the fuel rail. Then perform the following steps:

1. Disconnect the battery.

2. Remove the (2) 12mm bolts holding the black plastic wire cover.

3. Remove the small wire clips that hold the plastic electrical connectors to the injectors. This is possibly the toughest part of the job. Use the die pick in conjunction with the needle-nose pliers or a standard screwdriver. Be careful of the small plastic tab at the front of the connector. Also, do not drop the clips.

Injector wire loom clip.JPG

4. Slide the metal clips holding the injector to the fuel rail from left to right. Push first on the front part of the clip, then the rear with the long screwdriver.

Injector fuel rail clip.JPG

Fuel rail clip 1.JPG

5. Remove the fuel pressure regulator. A T-26 Torx screw [ashm: mine was T27] and gently pry the regulator off the end of the fuel rail. It is held in by an o-ring. Mine was in there rather securely. Have an old rag underneath before removing as some gas will spill out from the rail.

Fuel Pressure Regulator 1.JPG

Fuel Pressure Regulator.JPG

6. Remove the (2) 14mm [ashm: 12mm] fuel rail bolts.

7. Carefully push the fuel rail up. The injectors are held in place now only by their o-rings, but they will be solidly in place. Work slow, maybe first at one end of the rail, then the other and it will pop up. (they were that solid i had to use a pry bar to remove the injectors)

8. Remove the injectors. They will still be attached either in the rail or in the intake. Either pull or *gently* pry them out. (again i had to use the pry bar to remove the injectors from the fuel rail)

Before installing new injectors, compare them to the stock injectors. Make sure the o-rings are the same size; the distance between top and bottom o-rings is the same; and overall construction is similar. If all appear fine:

1. Lightly coat the new injectors’ o-rings in motor oil to aid installation. Push the injectors into the fuel rail first.

2. Attach/slide the clips that hold the injectors onto the fuel rail.

RC injector & clip.JPG

3. Carefully line up the injectors into the plenum and gently push down on the rail until the bolt holes line up. Replace the (2) 14mm [ashm: 12mm] fuel rail bolts.

4. Lightly coat the fuel pressure regulator o-ring with motor oil and push into the end of the rail. Replace the Torx bolt.

5. Plug the electrical connectors onto the injectors and carefully replace the small clips.

6. Replace the wire cover and connect the (2) 12mm bolts.

7. Connect the battery.

8. Turn the ignition key to the accessory position to prime the fuel pump. Check for any leaks. Start the car. Check for any leaks.

RC Injectors installed.JPG

Added by ashm 10/04/2022: O-Rings

Fuel injector O-rings can degrade and start to leak over time, which can cause quite an impressive spray of fuel from the fuel rail connection when pressurised. Rockauto lists replacement O-rings as 0.296" ID x 0.574" OD, or 7.52mm ID x 14.58mm OD, 3.53mm CS (cross section). I believe the correct material should be Viton as it has good compatibility with petroleum. However it is only borderline tolerant of ethanol, which is increasingly included in standard fuel. NBR rubber is fairly compatible with both petroleum and ethanol, so may actually be a better option if you plan to run high ethanol fuel, but it may be inferior to Viton in other ways. Personally I'm sticking with Viton.