Fuel Distributor Piston

[cfassett]

Working on my 77 911, which was in someone's yard for 25 years, and trying to get the fuel system clean.

I pulled the fuel distributor today, after reading to be careful not to drip the piston. Well, this wasnt a problem, as the piston doesnt seem inclined to come out. At all.

How does one get a stuck listen out of the fuel distributor? I am looking at correct part, right? The gold colored knob on the bottom of this piece?

[cfassett]

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[Flat6pac]

Soak it in WD40 for a day and apply air pressure to the top center hole.
Not working, soak it more, keep trying, it took years to get that way
Set it on a hot plate and air pressure when warm.
You also might try tapping it in to get movement after the first suggestion.
Bruce

[john walker's workshop]

Grab the tit with visegrips after soaking on both sides for a while.

[boyt911sc]

You could try both Bruce’s and John’s procedures to get the plunger to slide out. Or some other tricks in the book. If all these did not help you, your last resort is to disassemble the FD and separate the plunger from the barrel. With some luck and perseverance, you might be able to get the plunger out of the barrel. This is the EASY part.

The difficult part is to get the re-assembled FD back without having any fuel seepage or leak and this is a serious obstacle unless you know how to rebuild a leak-free FD.

Tony

[cfassett]

I ended up letting it soak in the ultrasonic cleaner with carb cleaner overnight, and going at the plunger with a rag and pliers. It did come out with a little tug. And yes almost dropped it on the floor. That thing sure is slippery with carb cleaner on it! No gunk or scratches evident on the piston.

That thing sure fits tight! I'm going to let the dizzy soak in the cleaner a bit more and see what we have.

I did end up cracking the two halves apart slightly, about 1 mm, and then thought better of it and tightened it back up. Is there any gasket between the two halves I need to worry about or is it just finely machined metal?

[john walker's workshop]

Shouldn't have tried to split it. Hope you get lucky.

[47silver]

There are many posts on pelican about rebuilding these and none are for the faiint hearted.
Some use some type of varnish, laquer or proprietary substance to seal the halves.
They do not have a gasket between them.
Maybe someone who does these will chime in on the board to let you know what they use to seal them but if you split them apart they 99% of the time need resealed i think that is what John meant by getting lucky.
Fuel Distributor Rebuilds
CIS fuel distributer cleanout w/pics

[john walker's workshop]

I cleaned up the one on my 3.0 turbo a long time ago. They tend to collect sediment on the thin center plate. Quite a balancing act to keep everyting in place on reassembly. I used 574 in such a minute amount that it was barely visible, spread with a razor blade. Got lucky, because there was no info about them at the time.

[boyt911sc]

Originally Posted by john walker's workshop

Shouldn't have tried to split it. Hope you get lucky.

cfassett,

Are you rebuilding the FD yourself? Now that you have you broken the seal between the upper and lower housings, sealing them back together is not easy to achieve unless you have done it before successfully. Many have tried this project of rebuilding a FD and most ended up frustrated and failed.

I doubt if you could achieve putting the FD together without suffering fuel seepage unless you are very lucky. But there is a slim chance that you could be successful and get the FD sealed up.

What I don’t understand is why did you open the FD? Since you were able to free the plunger out from the barrel, you should have stopped there. And subsequently test the plunger movement and have a good FD. Keep us posted.

Tony

[cfassett]

Thanks Tony. Stupid is as stupid does, I guess. Actually, I cracked the case last night when I couldn't get the plunger out. I didnt get it out until this morning.

The injectors were NASTY, so I was thinking the distributor probably was as well. Then, like I said, I thought better of it, and quickly tightened the screws back up.

[eastbay]

I went through my FD and had no problem sealing it back up.

[cfassett]

Well, that's encouraging. Did you use a sealant, or just put it back together?

[Walt Fricke]

I don't believe Bosch used a sealant. Some type of varnish (Indian?)has been used, with varying results. It is good to hear that JW was able to use a microscopic layer of 574 - I may try that on one of mine.

Which I have not been able to seal, so I bought a good used one from Tony. Close, but no cigar, and close doesn't count. The first problem is getting the six little oval seals to stay put (a tiny dab of grease?), and then getting the other half of the FD to slip over these without messing any of them up. This is sort of like putting the cylinders over the pistons/rings. Then comes finger crossing as you hook it up so you can put fuel pressure to it.

In your case, since - one hopes - you didn't pull the halves apart far enough to get to where these oval rings are, you might be all right on that score. As long as not a micron of stray matter got in between the surfaces of that thin stainless plate, you may luck out. I suspect you are better off not trying to put any kind of sealer in there - the whole thing ought to be apart for that.

What are you doing to try to flush the FD? Carb or brake cleaner, plus air, backward and forward, might help once you have it back together.

[cfassett]

Thank you all! In my infinite wisdom, I have lost one of these tiny plastic baskets that go in the fuel injector hose holes. Anyone know what these are called and where to find one?

[cfassett]

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[E Sully]

Those small filters are difficult to find, best to place ad in parts forum.
Rebuild kits are available for the CIS fuel distributors https://www.ebay.com/str/Cis-Jetronic?_trksid=p2047675.l2563

[eastbay]

Originally Posted by cfassett

Well, that's encouraging. Did you use a sealant, or just put it back together?

No sealer, thought I would try that first. Those baskets are filters, several of mine were trashed so I put the whole thing back together with none of them.

[cfassett]

Good to know. I did end sifting through the trash and found the missing filter. Took a closer look at the others, and found some grime, despite the previous soak in carb cleaner and spray out.

[boyt911sc]

Originally Posted by cfassett

Good to know. I did end sifting through the trash and found the missing filter. Took a closer look at the others, and found some grime, despite the previous soak in carb cleaner and spray out.

An ultra sonic bath cleaner use for cleaning jewelry will do a good job cleaning these micro fuel filters. Use heavy duty Purple Green as solvent for a 10 min. run and they will look like new. Add heat and the result will be much better.

Tony