Fuel Injector O-Rings

[REDCAB911]

Hello to all!!
This is my first post.
I finally tracked down a gasoline odor, that was only present when first starting the engine. The smell would go away, after the engine had warmed up. I had a similar problem before with my 3.2, 911. What I found on the V12 was the very last fuel injector, near the firewall, on the drivers side, (Left Hand Drive) had a damp area around where injector plugged in. I could not tell if the small amount of gasoline was coming from the top o-ring, at the injector fuel rail, or if it was seeping from around the lower o-ring. There was not enough gas to run, or spray anywhere, just enough to be able to smell it and see that it was wet. After the engine had warmed up, the wet area dried, and there was no longer any gasoline odor. The car is a 1990, 750iL, with a little over 103000 miles. I imagine that I am going to have to replace the all of the o-rings on the injectors on the drivers side, in order to fix that one leaking o-ring. Is this correct? I would think it would be. Also, would you go ahead and do the other side's o-rings as well, or leave it alone, or do both fuel rails HAVE to be removed, in order to replace the leaking o-ring on the drivers side? Any advice will be greatly appreciated! Thanks a lot, Tony.

[CaptHerb]

Wait until shogun chimes in, I'm sure I've seen this write up before.

If your going to do one, might as well do them all. And clean the injectors while you have them out.

[Platinum4Life]

I cant help with a suggestion, but welcome to the board.

[shogun]

Hi Tony,

we meet everywhere
BTW: I sendt the pic of your nice flatnose 911 to my friend in Germany.

Back to BMW:
I assume that it is time to change the fuel lines and the return lines. There was even a recall for that and there must be a sticker inside your car that it was done, or it may have been removed. How to do and the info from BMW
http://www.bimmerboard.com/members/l...re%20Hoses.pdf

I did all that on my Highline, and while you are there and have removed the intakes see instructions on my website, also on Johan's site.
you can also change the O-rings on the injectors (I bought them from Autohaus Arizona, 50 cents or so a piece, buy some more as some break while installing them).
O-rings: buy some Vaseline, that helps to get them on easy, nice instruction is here
http://www.pelicanparts.com/BMW/tech...eplacement.htm

[shogun]

Basically, if an O-ring is defective, you have rough idle.

I just remember a case 2 years ago which we found on my buddy's 750
http://www.bimmerboard.com/forums/posts/116765/

[REDCAB911]

Merry Christmas Erich, yes we seem to meet everywhere!! It takes me some time to find some of the really helpful boards. I will have to check to see if any recall sticker is there for that service. It does not leak at all times, just when it is colder than normal. Then it only seeps till the engine is warmed up, then it completely quits. I had a similar type leak on an injector on the Porsche. I installed the new o-rings, top and bottom. I why it was leaking, but don't know why it took so long to start leaking. I guess enough age on the o-rings to finally make it leak. The cause, the fuel rail was actually bent or twisted a very small amount. These rails are very tough, but it was torqued just enough, not to be straight anymore. I believe the cause, was when I had to have the 1st-2nd sync. replaced after I bought the car in 1997. You could not get it into 1st gear, but there was plenty of power and torque starting off in 2nd, it was not really a problem. As soon as I could fine a good, somewhat local Porsche wrench, I had it repaired. Great job! But this is also where I think that the fuel rail got twisted a little. I think that the engine was actually moved around in the shop, with one of the engine hoists, but they used the fuel rail as a pickup point with one end of the chain, and it twisted the rail just enough to cause problems later on, about 6yrs later on. I discovered the rail was twisted, ever so slightly, when I replaced the o-rings and buttoned it all back together, and the thing still leaked at the same spot. Then I removed everything again, and checked the fuel rail with a straight edge, and it was just twisted a little bit, above that injector at the end of the fuel rail. I know why they used it as a lifting point, because these things are very STURDY. I had to use to 24" long nut wrenches, similar to a pipe wrench, but designed for large nuts and bolts, up to 8". I used a couple of them to straighten the rail back out, then reinstalled everything. All was then well and at peace in my Porsche's world.
Sorry about the ramble, back to the BMW.
When replacing the o-rings on the injectors, are the fuel rails designed so that only one side can be removed, without removing the other side? Or, would you go ahead and replace all the injector o-rings on BOTH sides, or just the ONE side that is leaking. If the recall service was done, would you then only replace the ones on the rail that needs to be removed and leave the others alone, as in: "if it ain't broke, don't fix it" Sensei, I will follow what you say to do. Thanks a lot to all, and a GREAT HAPPY NEW YEAR!! Tony.

[shogun]

Pics from Johan's site will help you, there you can see how to remove them
http://bmwe32.masscom.net/sean750/V1...ughIdleFix.htm
O-rings are easy to change on both sides, if you want.

If the recall service was done, would you then only replace the ones on the rail that needs to be removed and leave the others alone, as in: "if it ain't broke, don't fix it"

That requires a lot of time and fingers/hand like a surgeon master. So see the bold letters above

And get some sockets with built in magnets for the standard sizes of nuts and bolts. When for example removing the intakes, you can be guaranteed that the bolts will fall into the engine room without magnets and you might never find them again.
I just bought some here in Japan, 9 piece set, something like these here, but of course metric
http://www.harborfreight.com/cpi/cta...temnumber=4830
I also have bought small magnets of 2, 3 , 4 mm thickness and 3-6 mm wide, these can be used anywhere where I need them.