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Apologies as I'm sure there must have been postings on this subject but on searching I couldn't seem to locate it/them. So, please, what's involved in replacing the injectors? Is is an easy job that can be undertaken without dropping the engine? Thanks for your patience!
I just wanted to confirm here that doing injectors with the engine in the car is doable, and actually not that difficult. I just did it this weekend on a 996.2 (3.6L) engine. Few words of advice. First, you have to remove the air intake and lower the engine down as low as it goes (resting transmission on the crossbrace). Then I also removed both rear wheels because I found it convenient to reach #3 and #6 injectors to plug and unplug the connector from the wheelwell. On the driver side, just remove the secondary air pump, unclip the wire harness from the fuel rail, unbolt the two bolts holding down the fuel rail and lift it up. Before taking the injectors out of the head I used my blowgun to below away any dust/dirt to prevent it from falling into the engine. Also helpful to have access through the wheel well for that. Then remove the clips and take out the injectors. The injectors are hard to remove from the rail, and I didn't want to damage anything in the process, so I used a hose separation plier to pull the injectors out (
) One one of the injectors I use an O ring plier to help get it out of the rail. Just any pair of pliers that separates when you squeeze it. Then just lube the o-rings and put it all back together. I suggest plugging in all the injectors right before positioning the rail/injectors and pushing it all the way in. Most injectors can be plugged in once the rail is back in its positions, except injector #4. You have to plug it in before installing the rail because otherwise the engine vent pipe is in the way. Below is the picture of injector rail during removal from bank 2 of the engine. Bank 1 is similar . The fuel line going to the fuel rail is fairly flexible, so there is a lot of room to maneuver. Overall not too difficult of a project. You can see the white injectors still attached to the fuel rail.
I just removed mine and sent them off for service whilst the engine was out, it is possible with the engine in but I would suggest its not an easy job, lowering the engine a little would definitely help.
The rail and injectors take some force pulling them out with aging O rings holding them inplace
Thanks for the reference and link to Pelican. An associated question that's leading me to think of replacing the injectors........the car idles rough, sometimes. It's annoying and "sometimes" gets a little better when I throw some injector cleaner in the tank. Any items to check before going for the injectors that might be causing the rough idle? Car has had all it's regular servicing including replacement of the plugs and all coils.
How many miles on the car/fuel injectors? All kinds of things can cause a rough idle, including air leaks in the intake, clogged ICV, TB needs cleaning, broken oil filler pipe, etc. I would definitely look into some other areas before condemning the injectors.
I agree with DBJoe996, lots of things cause rough idle, vacuum leaks are very high on the list, also aging 02 sensors.
Plugs and coils usually cause misfires and will show on OBDII code reads. Missfire will cause rough idle but to a higher degree and cause codes.
Before condemning fuel injectors, I would check fuel trims, 02 sensor response, with Durametric, and check crankcase vacuum with manometer.if nothing found I would even check compression/leak down for balance. Then if all that test good, then pull injectors and replace/test for balance.
I just wanted to confirm here that doing injectors with the engine in the car is doable, and actually not that difficult. I just did it this weekend on a 996.2 (3.6L) engine. Few words of advice. First, you have to remove the air intake and lower the engine down as low as it goes (resting transmission on the crossbrace). Then I also removed both rear wheels because I found it convenient to reach #3 and #6 injectors to plug and unplug the connector from the wheelwell. On the driver side, just remove the secondary air pump, unclip the wire harness from the fuel rail, unbolt the two bolts holding down the fuel rail and lift it up. Before taking the injectors out of the head I used my blowgun to below away any dust/dirt to prevent it from falling into the engine. Also helpful to have access through the wheel well for that. Then remove the clips and take out the injectors. The injectors are hard to remove from the rail, and I didn't want to damage anything in the process, so I used a hose separation plier to pull the injectors out (
) One one of the injectors I use an O ring plier to help get it out of the rail. Just any pair of pliers that separates when you squeeze it. Then just lube the o-rings and put it all back together. I suggest plugging in all the injectors right before positioning the rail/injectors and pushing it all the way in. Most injectors can be plugged in once the rail is back in its positions, except injector #4. You have to plug it in before installing the rail because otherwise the engine vent pipe is in the way. Below is the picture of injector rail during removal from bank 2 of the engine. Bank 1 is similar . The fuel line going to the fuel rail is fairly flexible, so there is a lot of room to maneuver. Overall not too difficult of a project. You can see the white injectors still attached to the fuel rail.
I swore for 15 minutes figuring out what to do getting #4 in until I did what Boris1 did. “Doink, doink, sh**! Ouch! Clunk doink, sh**t! Hmmm.” Thanks for the helpful write up!
06-07-2018, 10:17 AM
Replacing fuel injectors
