Injector replacement tips

[93jdirty']

Cyliinder #3 has crapped out, So I am going to replace it using the dremel method and hoping for the best. Has anyone on here succesfully replaced an injector without pulling the plenum?

[yodawill2000]

I have ..be aware that the old injector is going to take a heck of alot of force to yank out.And release the fuel pressure before you pull it !!

[GerryO]

I now have a "bad" #5 cylinder (172K miles and after very recently replacing the timing belt, water pump and all) injector that I believe is even less accessible than your #3.

I'm getting quotes for all the gaskets that will be required to replace all six injectors, and the EGR and PCV valves, and the wife isn't going to be happy/is already unhappy.

The good news is that I lost my job (of almost 21 years) yesterday and will have plenty of time to work on the car, along with a long list of other things.

[misfit6794]

Like yoda said, you can dremmel it, but, those injectors are a major pain to pull out of the fuel rail. It makes it alot easier if you can take off the whole fuel rail to get them out. But you have to remove the manifold for that. Try not to strip the hex bolts that hold the manifold on.

[yodawill2000]

I didn't have to dremel mine ..I believe it was the middle injector on the passenger side If I recall.Its been awhile.

[93jdirty']

Mine is the middle cylinder on the passenger side as well? How did you get it out without a dremel. Needle nose vice grips? please explain so i dont have to buy a dremel

[yodawill2000]

The dremel is only needed if you cant get to the two phillips head screws that hold down the injector.

[Jakw]

Yeah, all the dremel is for is to get enough of the plenum ground away to remove the screws from the injector caps. I did number 5 with a dremel. Don't get me wrong, it was a *****, but I'd rather not pay a shop $800 to remove the plenum.

[GerryO]

Yeah, all the dremel is for is to get enough of the plenum ground away to remove the screws from the injector caps. I did number 5 with a dremel. Don't get me wrong, it was a *****, but I'd rather not pay a shop $800 to remove the plenum.

I'm VERY impressed. What other things need to be removed in order to get the Dremel tool in there in order to create access to the Phillips screws?

And don't forget to use penetrating oil on the screws and the injectors. I removed one easily accessible screw today using a 3/8" drive Phillips tip attached to a ratchet.

A plenum gasket runs only about $10 and if one injector has failed, what about the condition of the others that are the same age?

Our local dealership wanted $1,100 labor, plus parts, to replace one injector.

Maybe I'll round-file my plenum off-of-the-car in order to facilitate access to some new socket head cap screws for the injector hold-down plates.

When the transmission goes, the car is probably finally gone.

[yodawill2000]

Ive heard from a reputable source that he would rather push his J off a cliff than pull the plenum again.Kinda silly when a dremel and a steady hand can get any injector out.

[Jakw]

I'll try to remember what had to come off to get #5, but it's been a few months. Obviously you have to get the throttle cable cover off. You need to take the bolts out that hold the hard fuel lines down. If you can get them, taking the rubber fuel hoses off would make things way easier. I did it with them on and just kinda held them out of my way. Hmm...oh yeah, the coil pack needs to be disconnected and moved out of the way.

Personally, I knew the phillips head screws would strip with any screwdriver. I think I let them soak in PB Blaster for a pretty long time, and I actually ended up making room for an impact driver in there. It's kind of a wierd angle, so it took me a while to get it right. If you ask me, you'll need to make room.

There's a certain bit that most people use. It's metal and like, serrated kind of. Hard to describe, but it does the trick. I personally just whipped through a few of the sanding bits, making sure to get the shape right for the impact driver. A few taps got both screws loose, and the cap was off.

From there, SILICON lube. Let the injector soak in it overnight, just keep that thing sprayed down. It's worth the $4 you have to spend on the can.

Actually pulling it out is the real pain. The plastic will break if you're doing it this way. Everything is all slippery from the lube, space is limited, and you're hunched over in a way that makes it tough to get leverage. I personally had to have someone bigger than me do it. He could stand on the ground and reach it in a way that got enough leverage.

Once it's out, you're getting close. Vaseline on the O-rings of the new injector will help, it's what the shops use. Be careful/forcefull when getting the new one in the rail. DO NOT crack the plastic cap trying to hammer it in or something.

That's pretty much it. Get the cap back on, bolt the fuel lines back down, etc.

None of this is actually a really big deal, it's just a whole bunch of small, careful, 'don't drop the tiny bolt' type of crap. And for the love of God, don't replace the injector cap screws with the same/more phillips heads. Buy some allen key headed screws of the same size/thread and use those. If something isn't right with the new injector, you do NOT want to take phillips heads out again.

Please, don't hesitate with more questions. I'll help as much as I can. I'd seriously walk anyone through it if you were within an hour or two's drive, knowing how much of a pain it is.

[GerryO]

I really appreciate all of the past experiences, tips and suggestions. The hands-on work will start next week, with the repair/replacement parts arriving the following week.

Unfortunately I have a tendency to do things the hard way. Tell me this this is easier and less risky than all new belts, tensioner, water pump and oil seals?

And how is silicone oil any different than penetrating oil in terms of loosening the old injectors?

Nissan knew how long they wanted these engines to last and the botton-end is less prone to failure than the top-end? It's too bad they didn't design/build them to be worked on simply and inexpensively.

[Jakw]

Seriously man, I tend to screw stuff like this up, but I got it done in a couple days. How is silicon lube different? Hmm...I guess probably the way it acts with rubber (the o-rings). Don't sit there and try to save yourself under $5 and do it with something else. Get. Silicone. Lube.

It should be easier than all that other stuff you mentioned, yeah. Please take your time grinding. A hole in the plenum is bad news. Plenty of people have successfully done this, so don't sweat it. Just take your time and all that.