Rebuilding CIS-E Distributor....
 

I got a junk distributor I wanted to give a shot at rebuilding and replacing all the seals inside...

Anybody know how to get the control plunger out? and does the upper and lower chambers separate?

http://w124-zone.com/downloads/photo...d/rebuild1.jpg
http://w124-zone.com/downloads/photo...d/rebuild2.jpg
http://w124-zone.com/downloads/photo...d/rebuild3.jpg
http://w124-zone.com/downloads/photo...d/rebuild4.jpg

Got the little sucker.....Hit her gently with a rubber mallet after letting it soak in carb cleaner for 2-3hours.

http://w124-zone.com/downloads/photo...d/rebuild5.jpg

Now to separate the two halfs....It seems to be stuck on really good. A small screwdriver and a hammer won't seem to separate it...Anybody know?

Seems to me when I took one apart there was just a thin gasket in there.

Seen This?
http://www.porsche928forums.com/download/manuals/CISRebuild.pdf

You can get a new diaphragm gasket on stealbay

Yeh I saw that, I just cannot seem to get the two halves apart....

Hi
Keen to know how you progress!

i got one from the junkyard , the two halves were separated by a thin rubber diaphragm ( 560sel) I believe my 103 300 SE will have a metal gas kit.
regards
mak

The 2 halves are stuck on the threaded part sticking out the bottom. Back in the day I took a few apart to confirm my diagnosis of a rusted through diaphram/metering plate. At the time there were no repair parts and all manuals I read cautioned against separating the halves. I'm not sure what you hope to accomplish by further dis-assembly. The only internal seals are around the ports in the central metering tube and if they are leaking fuel would be leaking out the bottom of the unit.

Diaphragm Kit
http://cgi.ebay.com.au/BOSCH-FUEL-DISTRIBUTOR-DIAPHRAGM-6-CYLNDER-ENGINES-/290518132589?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item43a43ae76d

Seal Kit??
http://cgi.ebay.com/ebaymotors/VW-Cabriolet-CIS-Fuel-Distributor-Seal-Service-Kit-_W0QQcmdZViewItemQQhashZitem53d8e13ac4QQitemZ360120924868QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccesso ries

here's a rebuilder and source for parts http://www.specialtauto.com/mercedes-parts/index.html
I doubt they will be detailed but you can always ask them what they do "special" when rebuilding these...

John is a good man. Though he doesn't do the rebuilds personally. He sends cores out for rebuilds and keeps the results handy. If you have an obscure part, then he needs your core to get it rebuild. Most of the time, he has the rebuild unit in hand and will send it to you when he gets your core.

If you're lucky, he already has lots of cores for your part already and won't mind to send the part out after you've paid the core charge.

If you want to get on his good side, send him a few spare cores that you collect at the PnP. Though he won't pay you for them. They'll do better that way than by becoming scrap metal.

Thx -CTH

Awesome, great price on the CIS pressure kit. I need to order that!

http://www.specialtauto.com/delorean...essure-kit.jpg

Separated two halves....put it back together.

Gonna test it out today and check fuel pressures again with the new one.

http://w124-zone.com/downloads/photo...d/rebuild6.jpg
http://w124-zone.com/downloads/photo...d/rebuild7.jpg
http://w124-zone.com/downloads/photo...d/rebuild8.jpg

All seals are still pretty supple and everything is ridiculously clean in there....I just did a little carb cleaner action and left everything else alone.

Put it back together....Put in the car and no start.

System pressure is only 2.4bar.

So looks like no go. Separation of the two halves possibly leads to non-function?

was just going through the W124 service CD via the "new & improved" indices available came across item #9 here... http://w124-zone.com/downloads/MB%20CD/W124/Index/Misc.htm Kinda useful experience relevant here. -CTH

That is very interesting....funny I missed that!

That is a GREAT idea though. I just ordered a new set of injectors and I have an entire set of spare fuel lines. I will bend them all straight as they mention, hook up the new injectors and measure fuel flow so I can tell 100% that the fuel distributor is delivering equal flow.

I'm back....I was a little aggravated that I failed on this, so I took another attempt. I have been thinking about it logically for a while now and the 2.4bar system pressure just made no sense. It means it is simply not holding the correct pressure...so WHY? If I put the halves back together and the car ran like crap, then I understand probably due to differences in each spring, aka it needs some very fine tuning, but the complete lack of pressure was really irritating me....so I took it apart again --

When I took the distributor halves apart, the O rings around the center barrel were in pieces!! Maybe that is the reason as to the failure then?

So....I decided to do the following as a last attempt:

First get some B12 Chemtool and soak both halves of the distributor for a number of hours:

http://www.w124-zone.com/downloads/p...ibattempt1.jpg
http://www.w124-zone.com/downloads/p...ibattempt2.jpg

and the elusive micron filter....looks fine to me, but NOTE the small hole in the barrel? Gotta line this up dead on, not much room for error!!
http://www.w124-zone.com/downloads/p...d/distrib1.jpg
http://www.w124-zone.com/downloads/p...d/distrib2.jpg
http://www.w124-zone.com/downloads/p...d/distrib3.jpg

This weekend I will be finishing up my fuel tank and give this baby a roll -- maybe I'll hit a jackpot!

Just figured out how to align the (metering?) hole....I believe this hole is the reason why people fail to "properly" dissemble and reassemble together. They either miss the hole, or accidently spin the barrel in the shaft causing a complete lack of fuel entering the distributor.

Oh man I can't wait now :D

http://www.w124-zone.com/downloads/p...rel-lineup.jpg

that thing kinda resembles a flex disc. :)

Are you going to replace the squared-off looking o-rings on the barrel there and inside the barrel bore? And all the other ones as well? They look a bit old. If I were going to the trouble I'd try and find some replacements made from Viton. Also, carb cleaner is bad for o-rings,especially if they are plain old nitrile and not Viton. It's hard for me to understand how that one is junk. Looks like a new one.
But good on you for doing this exploratory work. I was always under the impression these were not rebuildable. My fingers are crossed for you.

OKAY I think I've completely figured it out now (at least in my head anyway).

Building on what I just mentioned, I think i've figured out why my previous attempt failed. What happens is that when you tighten the screw in the photo, it causes the barrel to to move around. Even a few mm of movement means that it is no longer aligned and the car won't run.

I noticed though that there are two notches that you can use for reference. I confirmed the position by again using the safety pin to push through both holes, then tightening whilst keeping the pin in the hole so that the safety pin keeps the barrel in place.

The distributor has the Shellac gasket, all springs in place and now the metering hole aligned. If this fails I GIVE UP LOL. I have a really good feeling now though :)

The empty box is where the barrel notch should lie. Just slightly left of the slit in the distributor. Use the safety pin to ensure it is completely aligned though, but at least now your adjustments are within a a couple degrees of movement instead of 355 degrees of movement :)

http://www.w124-zone.com/downloads/p...ungerscrew.jpg

I replaced ALL O-rings using a Nitrile O-ring kit from Harbor freight. It had all sizes needed!

---

I got it from the junkyard, but took a good cleaning.

Interesting. I tried to pull apart a FD once, but the halves were rusted together I think. I love the mechanical simplicity.

So what do they do to rebuild these other than replacing o-rings/gasket?

Flow test each port. The hex screws on the bottom are so each chamber flow can be adjusted individually so you can ensure equal fuel flow going to each injector. That is something I think is possible to DIY, but without a true flow bench, it's gonna take a lot of time and adjustment taking it on and off the car... :cool:

First step now though before that is to cross my fingers and hope I can get the 5.1bar pressure instead of the 2.3 before.

2.3 makes sense though....if the barrel was not aligned, there would be simply a buildup within the barrel and a leakage into the lower chamber, instead of the pressure going directly from the barrel to the lower chamber. Much more direct.

I was looking at the Porsche documents for rebuilds, but the difference is that the "metering hole" for them is between the two bases instead of the barrel like these. I think this is the reason for much confusion and mystery.

We will see this weekend. If this works, I'm taking apart my rust-clogged distributor to take a look at the micron filter in that one. I have a brand new CIS Flow Tech distributor ready to go, but I'd much rather put a donkey on first.

The little hole does not matter. Note the groove around the cylinder. The fuel fills the groove and finds its way out the hole in the bottom half. It's the six other holes that need to line up with the input holes on the top half. If you want to use the little hole to index, fine, but understand what really needs to line up here.

Don't straighten the lines. Follow the procedure I added to your website and have since updated on this site and you can match all of the flow rates in "as the car will run" trim. Note that my update on this site has the flow specs. Same title: CIS-E Tuning I will add that info to your site as well one day soon.

EDIT: I love that you do this and post pictures. Your information will help quite a few people in the future....maybe even help you as you forget some of what you have learned, like the rest of us who are old enough to be your dad. :-)

In that case, it may be even easier to rebuild distributors then!

Simply leave the bottom screw alone which will keep the barrel locked in the same place at all times -- You could then safely separate the two halves, clean and backflush the micron filter and replace the 6 o-rings (removal of the o-ring down in the barrel would not be possible though), apply gasket sealant and put back together.

OR, remove the barrel completely line it up and tighten the screw before putting the halves back together. I may need to separate mine again now....

I think we are slowly cracking it... :)

I enjoy posting photos as they really do say a 1000 words and for future reference it is a great resource. You never know when the photo of an engine may provide information for future repairs, or position of items etc...they are invaluable in my mind. I have probably 5-6GB of photos stored now on my server over the last few years. I always save uncompressed ones too since you never know when you may need to zoooooooom in ;)

So nothing in that middle cylindrical piece pictured wears, then? Very simple "rebuild" at that point.

:)

Just wait until your monowiper fails and you take that apart.

You've got this one solved...for the most part. Now you need to make sure you have the plunger protruding the correct amount. The flapper should NOT contact the plunger while the car is idling. It's a feel thing.

p.s. As another poster mentioned, B12 is aggressive. I only soak all metal pieces, never pieces with plastics or rubber or paint, etc. The carb cleaner comes with a little tube to direct the flow. That is usually enough to spot clean the gunk that can't wipe or "brake clean" off.

Looks like the two halves have sealed awesome and the 6 holes are aligned now, only problem is the plunger doesn't seem to be dropping like it used to. I shot carb cleaner at it again, but its still not moving down by itself in the barrel.

Is there a sort of lube I should use to get it moving normally?

I saw that you replaced ALL of the orings. Including the plunger seal? It is not a round oring but instead has a shaped cross section and should not be substituted with a generic.

The one I removed was definitely round. I remember checking...so I think I'm in the clear...

where you succesful? What are the results?

Have not tried yet because the plunger once dry doesn't move in the barrel smoothly. Not sure if there is a trick to getting it right?

The plunger should not be an issue if it extends under pressure. You and your dad or a friend can plug up all of the outlets with your finger tips and use some compressed air at the inlet.

I build a number of heads and the "old" stem seals are always "free" but still work. The new stem seals always hold tight for the first few hours. I use Viton on the exhaust side. I suspect you are fine if you can pull the plunger or make it move with 50 psi.

That said...you MAY need to make an adjustment to the CO/idle screw as the O-ring frees up.

Well I was concerned over it because the one I just received back from CIS Flow Tech -- the plunger moves freely, but I did notice that the whole unit had a film of grease, I was just wondering if this is the grease that is used to keep it moving freely when not under pressure.

I'll be able to test my rebuilt one in about a month, so I'll report back soon. I'm excited to test it out, but gotta move out of where I am living first.

Grease or oil has never helped make my valves slide through new seals the way they slide through old ones.

Options are:

The rebuilt FD reused the old O-ring
duxthe1 is correct and the O-ring used in the rebuilds is not the same as your HF version

Either way, how could it matter? (Rhetorical)

The plunger does not come in contact with the o-rings though...so it should make no difference?

The o-rings are on the outside of the barrel....

I would not be *too* concerned with the plunger. It will behave completely different when the fuel system is pressurized. I have pulled a lot of FD's from junkyard cars, and the static plunger behavior varies from car to car.

Fair enough. I'll just wait til I get it tested in the car.

Old thread but it needs an update.

Are you changing the big black rubber part that goes between the upper and lower part?
or you are just re-using your old one?

I did my the FD rebuild twice, once on my 3.4 AMG and once on a freind 420 SEL and didnt face those problems.

Plunger reassembly
 

Hi,

I saw the brilliant pictures g the 560 bosh KE-Jetronic Distributor with the nut which hold the plunger and barrel in position. I took mine appart and did not record the position of the nuts. You got the outer ring nut which holds the barrel in place and then the innter one with the rubber seal which screws inside the outer nut. You can set the inner one deeper of higher into the out one. What should be the correct position.
For example i presses the inner nut (the bruubr ring side) as far as it would go into the barrel and then turned the outer one over it till t seated on the distributor housing. one can however with a screw driver turn the inner one out again. (Hope I made sense here)