Author Topic: Removing stuck fuel injectors  (Read 9479 times)

Offline jspicer6

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Removing stuck fuel injectors
« on: May 08, 2013, 06:43:56 PM »
Hi there, hope someone can help

Has anyone on here had trouble removing injectors from their engine? I've been trying to resurrect my K75 after being laid up for 3 years. Haven't been able to get her started, so was trying to remove the injectors, which wouldn't budge at first, but did come out after a while. However, the end of the injectors, with the lower 'o' ring is still in the head.

Q.1  Does this mean the injectors are now broken?

Q.2  How do I remove the lower part of the injector from the head without stripping the engine?

Thanks Jason

Offline Scott_

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Re: Removing stuck fuel injectors
« Reply #1 on: May 08, 2013, 07:37:08 PM »
It's not in the head per-se, but the boot is remove-able if you want to try and dig out the rest of the broken injector without having bits end up in the head.
You will have to remove the throttle body assy from the top of the boots, then the single boots can be removed from the head.

If they haven't been replaced lately there is an O-ring on the underside of the boot that seals them to the top of the head. If you take it all apart to get the boot out, you might want to consider replacing all the O-rings.

Yes the single injector is probably broken, but I believe that replacement injectors are available now that will work with our bikes now.
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Offline billday

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Re: Removing stuck fuel injectors
« Reply #2 on: May 08, 2013, 11:09:18 PM »
It's not in the head per-se, but the boot is remove-able if you want to try and dig out the rest of the broken injector without having bits end up in the head.
You will have to remove the throttle body assy from the top of the boots, then the single boots can be removed from the head.

I believe this is true only of the 4-valve k's. If this is a 2-valve K, the tip of his injector is well and truly buried in the engine block.

If they haven't been replaced lately there is an O-ring on the underside of the boot that seals them to the top of the head. If you take it all apart to get the boot out, you might want to consider replacing all the O-rings.

Replace all the O rings every time the injector comes out. There's an alternate to BMW listed in the Alternate Parts List in the Lieberry.
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Offline mjydrafter

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Re: Removing stuck fuel injectors
« Reply #3 on: May 09, 2013, 07:46:44 AM »
What does the injector look like that you removed? 

Here is what the complete one looks like:


Is it missing just the o-ring or the o-ring and both of the plastic pieces (orangish pc above the lower o-ring & the whitish bottom pc)?  You should be able to see the o-ring and perhaps the top plastic piece, if the bottom piece came off it might be a problem.  A hooked piece of stiff wire, or other hook or pick should get the o-rings.  Those end caps would be a challenge, if they are still in there.  They don't have a big enough hole to hook, if you could get them turn side ways you might be able to hook them out, but it's not going to be real fun.
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Offline billday

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Re: Removing stuck fuel injectors
« Reply #4 on: May 09, 2013, 07:50:30 AM »
Jspicer6, you should tell us the year and type of Brick we're talking about.
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Offline jspicer6

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Re: Removing stuck fuel injectors
« Reply #5 on: May 09, 2013, 02:38:20 PM »
Thanks for the info everyone. The bike is a '95 k75rt. In the photo of the injector the white piece and bottom 'o' ring didn't come out when I got the injector to move. So far I've got two out like that but the middle injector is jammed solid. I guess now that all three are scrap so might try getting the bottom piece out with a screw extractor.

Offline JamesInCA

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Re: Removing stuck fuel injectors
« Reply #6 on: May 09, 2013, 05:43:54 PM »
I haven't done this, so this is theoretical advice. YMMV.

You might try (carefully) turning a long drywall screw into the white thing stuck in the head and then pulling back on it. Or a long wood screw -- something with nice, wide threads.

The injectors themselves may be salvageable. Those three parts at the bottom (white pintle cap, brown o-ring, and orange spacer) are all replaced in a normal injector cleaning. So as long as the injector bodies themselves are ok, you may be fine. Once you get the third injector out, you can send them all to mrinjector.us, or similar shops, for inspection, cleaning, and new seals etc. Mr. Injector just did mine and has done many others with lots of thumbs-up.

Refurbished injectors are also pretty widely available from those same shops, and on eBay. (In this case, "refurbished" basically just means cleaned up the same way they'd clean yours if you sent them in.)

For that last injector, maybe you could get a vise-grip or pair of channel locks onto the top of the metal body (not the white plastic at the top), and rock it back and forth a little to loosen it up.

And lastly... there's undoubtedly a bunch of gunk in those injector holes, which you'll want to clean out once you get them clear, and without letting crud fall into the head. My tip on this: When I cleaned them out after removing the injectors, I took the shop-vac, with the smallest detailing nozzle I had, and held it right next to the hole while I swabbed the muck out with q-tips moistened with mineral spirits. The mineral spirits did a great job of removing the crud, and not a problem if a little drips in; it'll just burn up. Holding the shop-vac nozzle there helps draw any loosened bits upward, rather than letting them fall into the head. Come to think of it, you might even want to do that before removing the stuck caps and o-rings, as those will help block other stuff from falling down in.

Offline K75RT Keith

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Re: Removing stuck fuel injectors
« Reply #7 on: May 11, 2013, 04:42:57 PM »
FWIW  When I did my injectors they were really tight and I thought they were stuck.  It may take a fair amount of effort to get them out.    If they've been in for years they aren;t going to come out easily.   Before you do take them out, clean as much crud away from around each injector You might go as far as to take a small pick and go around the base of each injector to loosen 20plus years of grime, then use a vac and a rag to minimize the potential junk that could fall into the holes. 
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1990 K75RT

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