#7 Injector Change - need advice, cautions, etc

[Mikesinfiniti]

I'm changing my #7 fuel injector this weekend and before jumping into it, I'd like to get some advice from someone who has done the change already. What should I watch out for? What needs to removed to get to the injector? What do I use to lube the new injector o-ring? How long did it take? Is it as hard as it looks? etc.

Just looking for some help before I get started.

Thanks.

Mike

[goody90q45]

I did #7 a couple of months ago and it was my first time removing the plenum. I followed the instructions in Q45.org.

You don't have to remove the plenum completely but just remove enough attachments so that it will shift a few inches with a couple of the vac hoses still attached. Remove the TB, EGR and IAC. Clean all 3 while they're off and have new gaskets for all three for the reinstall. Remove the 16 plenum bolts. You're probably going to want to replace the 8 intake manifold gaskets also. At this point the plenum will lift but there's a couple more hoses attached to it (PCV valve) to shift it enough to get to the injector.

In hindsight, it wasn't that difficult a job. I am mechanically challenged and still finished up in about 6 hours with all parts cleaned and numerous short breaks. Take good notes with particular attention to where hoses attach for each of the 3 subassemblies you've removed. I've changed four injectors so far using Vaseline as the o-ring lubricant and they've all seated just fine. Good luck.

[Q451990]

Don't forget to pull the fuel pump fuse while the car is running to allow it to burn off all of the fuel in the rails and line. Also, remove the gas cap so that there's no chance of pressure building up again. You don't want to have fuel draining from the rail into the cylinders and causing hydrolocking... and you also skip spraying fuel on yourself and under the hood!

Heath

[JedCoop]

I changed the #7 injector on my G50 without removing the plenum. Not sure it was worth the hassle, though, to get to the one hard-to-get screw holding down the injector. If I were to do it again I would just remove the plenum bolts but not totally remove and disconnect it much like goody94Q suggests. But you don't need that much more room to get to the screws and pop the #7 injector out. So I doubt you need to remove the TB and IAC, but you may need to disconnect the EGR to get enough sidewards movement.

A little depends on your plenum gaskets too. I have changed mine, so they were not so old, and felt sure they would still reseal well. If your car still has the originals, the old plenum gaskets may work fine, but I haven't tried that. Also buy them before you start the job from Scottsdale... the local dealer charge me $10 for one when I accidentally damaged it, and needed a replacement quick.

Good luck.

[Mikesinfiniti]

Thanks guys for the tips. I have not started fearing I did not have a whole day to do the job (or at least 6 hours as Mike says). I may give it a few hours today and finish up tomorrow. The car's in the driveway and I already have the IAC off when I tested the injector so I'm stuck with it in the driveway, so the weather is a factor.

Thanks again.