fuel injector fittment

[blk911]

I have tried to search the threads and just didnt see it addressed, so here goes. I was looking things over on my 79SC with about 83,000 mile on the clock and noticed that the fuel injector fittings seem loose to me. What I mean is that I can twist the fitting back and forth by hand. that just doesnt seem right. Shouldn't they be rather snug?

The car runs great with the only problem being a hard hot start after sitting for 30 minutes. I will probably go ahead and replace the fuel pressure accumulator.

[DRACO A5OG]

You sure it is not cross threaded or if the injectors are same thread as the old ones?

[blk911]

I did not replace the fuel injectors, was just checking condition of the fuel lines from the WUR and noticed the fittings seemed loose. I have had the car eight years and no work done on the fuel system in that time. I tried to pull the fuel lines off to see if I could tighten the fittings but they were stuck pretty tight and so I thought I had better figure out what the proper procedure is before I screwed something up.

[boyt911sc]

Blk911,

Hard to imagine a loose fuel fitting in a fuel injection system that would not leak. Could you post of the said fitting? Thanks.

Tony

[al lkosmal]

Take a picture of the fitting(s) you are referring to. Are you referring to the fittings on the ends of the fuel lines that thread onto the injectors or the fittings in the port that the injectors are pressed into....or?



regards,
al

[blk911]

Sorry for the picture quality, but this is the fitting on what i think is Cyl#1. Starboard side, rearward most cylinder. The whole fitting just easily rotates in the manifold. Thank you for your help and comments.

[blk911]

sorry again, first time to upload a picture. Thank you for being patient.

[DRACO A5OG]

Is that the only one that is loose?

[blk911]

no, the next one toward the firewall on the same bank is equally at loose. I can spin the fitting in the manifold, but the fuel line to the fitting and the fitting to the fuel injector are tight. Maybe just worn o-rings? Tried to pull the fuel injector with quite a bit or force, but did'nt budge. Fuel lines from WUR look to be in good shape, but concerned about vacuum leaks at the injector fitting.

[DRACO A5OG]

Well to test your theory, spray some ether there to see if idle changes???

[boyt911sc]

Originally Posted by blk911

sorry again, first time to upload a picture. Thank you for being patient.

Blk911,

Are you referring to the rusted part in the picture as the fitting in question? That's the fuel injector that sits on the sleeve and held by an O-ring. Once the rubber O-ring/s dried up and becomes hard, those CIS injectors would be free to move or rotate and start to cause vacuum leak/s.

BTW, that intake manifold in the picture is for cylinder #4 and not cylinder #1. Look closely and you'll see the AAR (auxiliary air regulator) in the background. Time to replace those old and worn out o-rings.

Tony

[blk911]

Draco, thanks for advice, so if I spray ether, and assuming I don't go kafoom! that would indicate a leaky injector o-ring? Sorry for being nervous, is there a safer test than spraying ether?

[DRACO A5OG]

Nice :-)

[timmy2]

If they spin by hand the o-rings are done... I just checked mine that are a year old and they don't turn at all by hand.
Order new o-rings, pull out the injectors and install new o-rings. Easy job with engine in car.
Might want to replace the injector sleeves and their o-rings in the intake runner as well. Not as easy a job...

[boyt911sc]

Originally Posted by blk911

Draco, thanks for advice, so if I spray ether, and assuming I don't go kafoom! that would indicate a leaky injector o-ring? Sorry for being nervous, is there a safer test than spraying ether?

See and read the recent post by Thomastee how he located the air leaks in his CIS.

Tony

[DRACO A5OG]

Originally Posted by blk911

Draco, thanks for advice, so if I spray ether, and assuming I don't go kafoom! that would indicate a leaky injector o-ring? Sorry for being nervous, is there a safer test than spraying ether?

Use very little at a time, the ether will get into your intake and give you a false positive. Caution insure you have no errand sparks.

[James Brown]

time to get the fiber insert and new o-rings, there is only vacuum in the intake (or should be). Change them all, might improve idle.

[blk911]

Thanks to all for your help. Yes, Tony, it is the rusted part, which I now realize is actually the injector.

One more question; the hard plastic fuel lines just dont want to come off, if I cut them does that cause a problem? I don't know if they are equal length and need to stay that way?

[James Brown]

no need to cut them, hold the injector with one nut wrench and turn the hose nut with another. The black fuel line should not turn. If it does, try some spray lube to knock the rust loose, work the flare wrench back and forth to break the corrosion seal. you can get the fuel injector hose to replace as needed.
Or you can pull the whole assembly out and change the O rings/fiber insert. they just pry out. there is a porsche/bosch tool for that.

[blk911]

James,

thank you very much. I have no idea how long they have been in this condition, probably a while. Maybe cold idle will be a little less lumpy now. :-)