Fuel Injector O-ring question.

Post by **snobrder** » Wed Jul 30, 2008 6:53 am

I am ready to replace injectors 1 and 2 for now. I have the new injectors, can I just remove the old ones and put the new ones in or is there some in between steps?

Post by **goody90q45** » Wed Jul 30, 2008 7:16 am

It's always recommended to use new o-rings for any repair you make but if you're going to reuse them at least examine them closely with a magnifying glass. If there's any nicks, cuts, wear, flat surfaces, etc. they should not be reused. Heavily lube the FI grooves and the orings with vaseline so you don't nick them while stretching them on to the FI- especially the large o-ring.

Post by **snobrder** » Wed Jul 30, 2008 7:23 am

Well I have new large o-rings on the top of the injector. Are there more o rings?

Post by **goody90q45** » Wed Jul 30, 2008 7:50 am

There's also a smaller o-ring on the bottom side. Y\If it didn't come out with the old FI you'll probably find it laying inside of the fuel rail cup it came out of.

Post by **snobrder** » Wed Jul 30, 2008 8:41 am

Damn these things suck...i got the two screws for #1 off fine but ofcourse #2 had to strip. I am going out to buy screw removers and some PB blaster because WD40 didnt cut it.

Post by **Q451990** » Wed Jul 30, 2008 8:47 am

Vice grips have always worked well for me. Those screws are terrible... IOS kept a supply of appropriate hex head screws in stock to use as replacements.

Go ahead and get new o-rings. Taking a chance on hydrolocking your engine over a $3 part isn't worth it!

Another thing I learned is that in addition to pulling the fuel pump fuse and running the injectors dry - you need to loosen the gas cap. The tank will build pressure, especially if it heats up, and will force fuel out of the rails (or disconnected hoses) and make a mess.

Good luck!

Heath

Post by **snobrder** » Wed Jul 30, 2008 9:01 am

Q451990 wrote:Vice grips have always worked well for me. Those screws are terrible... IOS kept a supply of appropriate hex head screws in stock to use as replacements.

Go ahead and get new o-rings. Taking a chance on hydrolocking your engine over a $3 part isn't worth it!

Another thing I learned is that in addition to pulling the fuel pump fuse and running the injectors dry - you need to loosen the gas cap. The tank will build pressure, especially if it heats up, and will force fuel out of the rails (or disconnected hoses) and make a mess.

Good luck!

Heath

Hey man thanks for the tips. I really want to get the car fixed asap, think it would be alright to just go to AA and buy these? http://www.partsamerica.com/pr...PTSet=

Post by **Q451990** » Wed Jul 30, 2008 5:21 pm

Those look like the ones for the 94-96 style, which would be the wrong size. Could just be the picture. Just make sure you get the right ones.

Do you have a dealership nearby? Should be about the same price... Nissan dealership is a good possibility too, since the 300ZX (TT?) used the same injectors. The lower o-ring is more critical than the upper one. A leaking lower o-ring will let gas out around the injector tip and flood your engine. An upper o-ring leak will cause fuel to leak around the top of the injector cap and out of the rail... makes a mess and is a fire hazard, but if you catch it at least it can't bend a rod or ruin your engine.

Just be very careful since you won't be able to detect a lower oring leak since you're not pulling the plenum and rails.

Heath

Post by **snobrder** » Wed Jul 30, 2008 5:52 pm

Q451990 wrote:Those look like the ones for the 94-96 style, which would be the wrong size. Could just be the picture. Just make sure you get the right ones.

Do you have a dealership nearby? Should be about the same price... Nissan dealership is a good possibility too, since the 300ZX (TT?) used the same injectors. The lower o-ring is more critical than the upper one. A leaking lower o-ring will let gas out around the injector tip and flood your engine. An upper o-ring leak will cause fuel to leak around the top of the injector cap and out of the rail... makes a mess and is a fire hazard, but if you catch it at least it can't bend a rod or ruin your engine.

Just be very careful since you won't be able to detect a lower oring leak since you're not pulling the plenum and rails.

Heath

No dealerships nearby, the reason I want to go with AA is because I can get some good discounts. I just check the 90-93 and the 94-96 and they are different kits, on the 94-96 shown http://www.partsamerica.com/pr...Set=A the one piece is much bigger than the 90-93 here http://www.partsamerica.com/pr...PTSet

Post by **goody90q45** » Wed Jul 30, 2008 6:08 pm

The large, upper o-rings on both injectors are the same.

Post by **maxnix** » Wed Jul 30, 2008 6:50 pm

snobrder wrote:No dealerships nearby, the reason I want to go with AA is because I can get some good discounts.

But are they OEM specification?

AA in particular is the king of retailing inferior Chinese copy products. It's your car.

Lots of ex owners not here anymore because they saved so much money on non OEM parts.

Post by **CINNALOCKS** » Thu Jul 31, 2008 2:51 am

Just FYI, I used a Napa Shop, they said they knew what they were doing this was five years ago before I was a member here. They did the injectors but forgot to reinstall both o rings and it cost me the engine.

Luckily it was a AAA recommended and certified shop. I got AAA involved and got another engine installed at a cost of $6,700 all billed to the shop's insurance company. Just to let you know it does not pay to cut corners on parts or the service people.

You have a luxury car, treat it like what it is and it will serve you the way it was meant to. Cut back on parts and cheap shade tree mechanics and you will be left on the side of the road, parked in the garage or at the curb.

Post by **sdkhalsa** » Thu Jul 31, 2008 5:34 am

When I replaced the first batch of injectors I had a stripped out screw on the injector cap that defied the vice-grip solution. I drilled off the head of the screw, lifted off the cap and was then able to get a good enough grip to twist out the remains of the with a large pliers. Following this experience, I changed out all of the cap screws. By the way, when I loosen the screws, I normally tap lightly on the top of the phillips head driver with a hammer as I twist. This works great for the difficult ones, and helps avoid stripping them.

Post by **snobrder** » Thu Jul 31, 2008 5:38 am

Thanks for all the help guys. I should of asked before I started lol. I am just gonna wait till I will pull the plenum and just pull the rail to be safe and not **** anything up. The only thing stopping me from pulling the plenum is the fact that I am horrible at staying organized and I am afraid I might start losing parts or something.

Post by **Q45tech** » Thu Jul 31, 2008 6:14 am

Why even the best technican have plastic parts trays with ice cube blocks for related parts.

16 bolts for plenum runner, 8 of this and that.

Wall sized enlargement of under plenum hose routing pictures. When you do a hundred a year you learn.

Post by **snobrder** » Thu Jul 31, 2008 6:27 am

See now that is a good idea and something that will help me alot. Thanks, now I will try to study the hose diagrams and what not to get motivated to finally do it haha

Fuel Injector O-ring question.

Fuel Injector O-ring question.

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