How To Remove Fuel Injectors
It's not hard, but my experience is limited to two removals of one
leaking injector and one removal of its bracket-mate (they are held in
as injector and one removal of its bracket-mate (they are held in as
pairs). You just get a 7/16" socket wrench with a universal joint for
the inner ones and abox wrench for the two end ones (due to the fuel
rail's design). Also get as many 1/4" vacuum-line caps as injector hoses
you'll disconnect from the fuel rail.
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
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.