How To Remove Fuel Injectors

The worst part is the first -- get two teeny-tipped screwdrivers and pry apartthe spring clip on either side of the injectors' connectors to allow removal. Sometimes the locking glop of plastic on the top of the connector is gone and the U-spring will just slide upward -- nirvana. Pull off the connector andthe U-spring will just slide upward -- nirvana. Pull off the connector and inspect it for cleanliness and boot cracks. The latter can be filled with Superglue Black Plastic Rubber, which will dry while you're working on the rest of the task.

Remove the two nuts from the bracket holding the pair of injectors you're targetting (don't drop them down into never land below). The bracket can now slide back over the injectors' hoses. Disconnect the hoses from the fuel rail and cap the outlets on the rail with the vacuum caps. Remove the bracket,maybe clean it and paint it a tasteful color (if your wife is shopping, put it in the oven to dry fast).

Now pull back on the injectors -- they're just pushed into the intake manifoldand have a small rubber ring on the business end. Inspect the hole in the manifold with a flashlight and remove any rubber left there, cleaning the area with a swab and whatever solvent you like -- acetone is good, but will get at any paint you may have there.

The injectors have a larger ring that acts as a shock absorber, reducing noise conduction and allowing a convenient pressure control when refitting. Usually, you won't have to replace this if it looks ok, but others may disagree. If you do, note the position of the circular steel ring that holds it and the injector together. The large rubber ring can be removed by pulling back on the steel ring and using a small screwdriver to prise (like that word,so delicately forceful) the rubber ring off toward the injection end -- note how it was fully in a depression around the injector, so you can put the new one back that way. The small rubber ring must be replaced if good sealing is to occur. Coventry West and others have all these seals and used as well as new injectors. You can clean the injector surfaces with solvent and a wire brush. Then I use some silicone oil on the entire steel surface of the injector and the rubber rings to facilitate reassembling.

When putting the injectors back in, use a new length of 5/16" Fuel Injector (important) hose, and the proper, solid-surface clamps (I use oil/grease on the nipples and clamps to make things go together nicely). Old hoses can be cut off the injectors with a razor blade. Clean the injectors' electrical contacts with acetone on a Q-tip. Also, you can check them with an Ohmmeter if you want to be sure -- 2.5 to 3 Ohms is about right. Put a new, greased small rubber seal on the business end, if you haven't already, and push a pair of injectors carefully into the intake manifold -- careful not to pick up any goop from around the holes, aim is important and the silicone grease helps here too. Put the bracket back on so the injector connectors are up and aligned to make Martha Stewart proud, then oil and tighten the nuts with lockwashers (aircraft, nylon locknuts may not be best here, since the studs turn out easily). You tighten the nuts all the way down so the bracket touches the manifold at the studs and compresses the large rubber rings asmuch as possible. This forces the small seals at the end to properly fill the spaces at the business end.

Clean the connectors with acetone, as much as possible. Mark them with the cylinder #, just in case, and plug them onto the right injectors -- any removed U-springs can be slid onto them just before doing this. It's probably a good idea to put a small drop of durable glue on top center of any U-spring that was removed from its connector

Connect hoses and clamps, get a fire extinguisher and start the engine. Observe the injectors carefully to detect leaks in hoses, manifold seals, or at the plastic-steel interface on each injector -- that's where mine failed (epoxy didn't help this, by the way). Run the engine to normal heat while inspecting. If no leaks, drive a bit and inspect again. I'm sure others will have more advice.