Changing Fuel injector

[Mandar]

I bought '94 Q45 recently.It started vibrating wierdly and my drive to office is 65 miles one way. The vibration was bad enough to make me dizzy.

I got it inspected by an infiniti dealer. They said that fule injector #8 (white) has gone bad. They are charging abt $200 for a new fuel injector. I checked on the internet and found a Bosch for abt $85.

I am new to all this. Is it simple to change a fuel injector? And is it wise to buy and after market part rather than the infiniti part?

And where can I find detail instructions on how to do it?

Thanks in advance.

[911/Q45]

I just posted my experience in general.

[DAEDALUS]

1) Yes2) No

I can provide instructions later; remind me if I don't post some within a day. You can get a factory injector for about $145 from Scottsdale Infiniti 1-888-216-5328. Tell them yours is a white-dot injector and see if they can give you the same color.

[DAEDALUS]

1) Remove blue 15amp fuel pump fuse from fuse array near the hood pull handle.2) Start the car and let it die. Then crank it several more times.3) Remove the front plastic trim cover right in front of the plenum...3 10mm fasteners.4) Cut off the short length of fuel hose right behind the trim and drain the fuel rail into a container. You may even want to blow the rail out with compressed air at 30psi, but it's not necessary. Obviously you'll need a length of fuel injection hose to replace the removed one. Take precautions against fire.5) Carefully remove the metal harness clip from the injector's harness connector.6) Pull the harness off the injector.7) Remove the 2 screws holding the injector cap down. Careful, they're on pretty good and easy to strip. Some techs replace them with hex-heads.8) Remove the metal spacer from under the cap.9) The old injector can be pried and/or pulled out. Make sure you remove both o-rings. If you drained the fuel rail properly, very little fuel should drain into the intake runner. Whatever fuel drains down will end up in the oil pan and thin out the oil. 10) Place the new o-rings on the new injector and place a bit of grease on them.11) Push the injector into the fuel rail, orienting it like the old one, and being careful to not pinch either of the o-rings.12) Replace the spacer, noting flat-side orientation, and fasten cap down.13) Place the clip on the connector first, and then place connector on the injector.14) Install new fuel injection hose and replace plastic trim.15) Install pump fuse.

Make sure the engine idle's smoothly and keep an eye on the exhaust for excessive white smoke. If you get a lot of fuel drain down into the intake, don't crank the engine till you're sure the gas is out of there, and change your oil soon.

[Mandar]

Thanks Guys for the reply.And Daedalus esp.Taking heart from the fact that this group is there for support, I have decided to change the fuel injector myself.

When I order the new injector, will it have O-rings? or I will need to get them? Does it also have fuel injection hose?

So I will need:1. New white fuel injector2. Hose3. O rings4. greese or the likes? (which one and where to put?)

The service manual says that I should drain the coolant? Any specific reason?

I will need a torque-wrench and little else.

Thanks for the help.

~Mandar

[DAEDALUS]

You'll need to order the o-rings separately, usually they think to ask since seals always need to be replaced. The fuel injection hose can be bought at PepBoys or Autozone. Usually about $4/foot, and I think 5/16" will work. Generic assembly grease whould work fine. Put it on the o-rings so they slide better into the fuel rail. No need to drain the coolanat.

[911/Q45]

The coolant draining is in the case of complete plenum removal, which you're lucky enough not to need. I used Vaseline on the o-rings. I don't think you'll even need a torque wrench, the #8 injector is very accessable.

[Q451990]

One other suggestion... if you're working outside also loosen the gas cap! I left mine in the driveway in the sun while I was waiting for parts for a couple of days, and ended up with a "valley" full of gas! The heat caused the fuel in the tank to expand and pushed it out of the hose under the hood.

Heath

[Q45tech]

Many engines get destroyed [damaged] by in experienced people changing injectors filling the cylinders full of gasoline, hydrolocking and during cranking bending the rods!

[911/Q45]

I had good luck by pulling the fuel pump fuse and letting the car die, then opening the gas cap to relieve pressure and finally disconnecting the hose from the fuel filter to the hard line leading to the injector rail. If you do this while the engine is still hot, the gas will bubble out of the rail and evaporate pretty fully preventing hydrolock(petrolock?). Catch the gas in a cup and don't smoke while you do this!