How to do an injector change
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Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
Blow out all dirt around the injectors/holes in the intake manifold.
Remove clip that holds the two hardlines in the bracket at the rear/driver's side of the intake manifold. Its held on by a Torx head screw, and if I recall correctly, the screw head is facing down - a minor inconvenience.
Remove the vacuum line from the fuel pressure regulator
Press down on the valve core in the Schrader valve to relieve fuel pressure. Have a rag to catch the drips, and don't do it while the engine is hot.
Remove four bolts that hold the rails on the top of the manifold.
Release the wire bundle from the plastic clip that holds is to the top of the fuel rail and puch wire bundle to the rear.
Remove harness connectors from all 8 injectors. The spring clip get pushed "in" to release the connector. The connectors should already be numbered 1 though 8 to insure you put them back on the correct injector. (93 will not have numbers, because the connectors are not injector-specific)
Stand on one side of the engine, and reach across the top of the intake manifold and pull up on the rail on the opposite side of the engine. The rail should pull up, pulling the 4 injectors out of the intake manifold. If it doesn't pull out, it may require some gentle prying with a flat pry bar, under the rail. Be careful not to scratch up the soft aluminum of the rails and the intake.
When the injectors come out of the manifold, check to make sure that there is an o-ring on the bottom of each injector. If any of them are missing, fish them out of the hole in the intake manifold.
Move to the other side of the engine, and pry the other rail up. Check for o-rings, as described above.
Have a small pan available, and a rag, to catch fuel from the next step.
Slide spring clips that hold the injectors in the rail to the side. Pull injector out of the rail, making sure there is an o-ring on the top of each injector. When you pull the first injector out on each side, fuel will spill out of the rail. That's what the pan and rag are for.
Select a new injector, lightly wipe the o-ring with some light oil, and insert the top of the injector into the rail, sliding the spring clip back into the groove in the injector, to hold it in the rail. If you use the FMC, SVO, etc injectors, it may be difficult oi impossible to get the spring clips back on the injector. They are not essential, but make it easier to put everything back together.
After you have all the injectors in the rails, lightly wipe the lower o-ring of each injector with light oil, and line the 4 injectors on one side up with the holes in the manifold. Push the rail down, insuring the o-rings are sliding freely into the holes in the manifold, and not tearing.
Repeat on opposite side. At this point, both rails should be resting firmly on the top of the manifold.
Install 4 bolts that hold the rails on the manifold. BE CAREFUL. They are very thin, and will snap off if overtorqued. Find a spec, which will probably be in inch-pounds, and do not exceed it. (I checked my Chilton's and it shows 18 ft-lb. That seems "high").
Attach vacuum line to fuel pressure regulator
Pull wire bundle back over the rails and put it in the plastic clip that holds it on the rail.
Put the hard lines back in the bracket that holds them at the rear of the manifold, and install the clip that holds them in the bracket.
Plug the harness connectors back into the correct injectors.
May have missed some details. Perhaps anyone else reading through this can offer corrections/additions as necessary.
Remove clip that holds the two hardlines in the bracket at the rear/driver's side of the intake manifold. Its held on by a Torx head screw, and if I recall correctly, the screw head is facing down - a minor inconvenience.
Remove the vacuum line from the fuel pressure regulator
Press down on the valve core in the Schrader valve to relieve fuel pressure. Have a rag to catch the drips, and don't do it while the engine is hot.
Remove four bolts that hold the rails on the top of the manifold.
Release the wire bundle from the plastic clip that holds is to the top of the fuel rail and puch wire bundle to the rear.
Remove harness connectors from all 8 injectors. The spring clip get pushed "in" to release the connector. The connectors should already be numbered 1 though 8 to insure you put them back on the correct injector. (93 will not have numbers, because the connectors are not injector-specific)
Stand on one side of the engine, and reach across the top of the intake manifold and pull up on the rail on the opposite side of the engine. The rail should pull up, pulling the 4 injectors out of the intake manifold. If it doesn't pull out, it may require some gentle prying with a flat pry bar, under the rail. Be careful not to scratch up the soft aluminum of the rails and the intake.
When the injectors come out of the manifold, check to make sure that there is an o-ring on the bottom of each injector. If any of them are missing, fish them out of the hole in the intake manifold.
Move to the other side of the engine, and pry the other rail up. Check for o-rings, as described above.
Have a small pan available, and a rag, to catch fuel from the next step.
Slide spring clips that hold the injectors in the rail to the side. Pull injector out of the rail, making sure there is an o-ring on the top of each injector. When you pull the first injector out on each side, fuel will spill out of the rail. That's what the pan and rag are for.
Select a new injector, lightly wipe the o-ring with some light oil, and insert the top of the injector into the rail, sliding the spring clip back into the groove in the injector, to hold it in the rail. If you use the FMC, SVO, etc injectors, it may be difficult oi impossible to get the spring clips back on the injector. They are not essential, but make it easier to put everything back together.
After you have all the injectors in the rails, lightly wipe the lower o-ring of each injector with light oil, and line the 4 injectors on one side up with the holes in the manifold. Push the rail down, insuring the o-rings are sliding freely into the holes in the manifold, and not tearing.
Repeat on opposite side. At this point, both rails should be resting firmly on the top of the manifold.
Install 4 bolts that hold the rails on the manifold. BE CAREFUL. They are very thin, and will snap off if overtorqued. Find a spec, which will probably be in inch-pounds, and do not exceed it. (I checked my Chilton's and it shows 18 ft-lb. That seems "high").
Attach vacuum line to fuel pressure regulator
Pull wire bundle back over the rails and put it in the plastic clip that holds it on the rail.
Put the hard lines back in the bracket that holds them at the rear of the manifold, and install the clip that holds them in the bracket.
Plug the harness connectors back into the correct injectors.
May have missed some details. Perhaps anyone else reading through this can offer corrections/additions as necessary.
Last edited by Injuneer; Mar 27, 2008 at 09:23 PM.
Thread Starter
Registered User
Joined: Mar 2004
Posts: 158
But I am kinda confused on how you know to put a procharger on but not injectors?
I haven't even looked at injector change. I figured I would ask on the forum to get an idea. I could have walked my lazy *** to the garage and open hood, take a look but that would require me to get off my cozy couch!!
I haven't even looked at injector change. I figured I would ask on the forum to get an idea. I could have walked my lazy *** to the garage and open hood, take a look but that would require me to get off my cozy couch!!
Registered User
Joined: Jan 2008
Posts: 326
From: Topeka, KS
Haha, alright well that makes more sense. I was confused there for a bit.
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