Rebuilding CIS-E Distributor.... - Page 2 - PeachParts Mercedes-Benz Forum

ps2cho · #16 04-06-2011, 10:09 PM

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:

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!!

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

ps2cho · #17 04-06-2011, 10:48 PM

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

lsmalley · #18 04-06-2011, 11:39 PM

that thing kinda resembles a flex disc.

d.delano · #19 04-07-2011, 12:04 AM

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.

ps2cho · #20 04-07-2011, 12:56 AM

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

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.

JohnM. · #21 04-07-2011, 01:00 AM

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?

ps2cho · #22 04-07-2011, 01:07 AM

Quote:

Originally Posted by JohnM.

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...

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.

KJZ78701 · #23 04-07-2011, 04:26 PM

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. :-)

ps2cho · #24 04-07-2011, 04:42 PM

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

JohnM. · #25 04-07-2011, 04:53 PM

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

KJZ78701 · #26 04-07-2011, 05:07 PM

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.

ps2cho · #27 04-08-2011, 11:59 PM

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?

duxthe1 · #28 04-09-2011, 12:43 AM

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.

ps2cho · #29 04-09-2011, 12:45 PM

Quote:

Originally Posted by duxthe1

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...