Author Topic: Advice Preparing 4 Restart  (Read 900 times)

TNNBENZ

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Advice Preparing 4 Restart
« on: 07 October 2021, 10:34 PM »
Well after almost a year I am close to a restart of a 1977 4.5 !!!
I have acquired many 1979 fuel system parts as suggested in M117 manual. I plan to clean existing parts on the car that I did not upgrade.
   I have removed the air meter housing & fuel distributor.  Purchased a kit to rebuild cast iron distributor. After buying kit I found a good deal on an 1979 alloy distributor with a metering housing. Neither distributors fuel piston moves ! I read distributor is not rebuildable if piston is stuck.!!! I do not believe that !!! I think it is the ethanol in the gas gummed up, all it needs is a good cleaning. Is this logic correct ?
Have kit for current WUR. After I bought that kit i found another good deal on a 1979 WUR.
Bought new complete fuel system under car...fuel pump, strainer, etc under car.
   The car was last tagged I think in 2002. I removed a valve cover & chain seems tight enough, & no oil sludge ! Looks very well maintained. Best I can tell the plastic clip parts seem ok. Anti freeze looks clear and good to 30 or -30 I cannot remember. Plugs look new. Tires tread look new except dry rotted. Mucho expensive tires when new. Car has 90,000 miles on it. Someone either serviced this car recently trying to get it to run or it was freshly serviced & then parked for some reason. 
Advice is needed, should I clean & rebuild current parts and hope it starts. Or clean & use the 1979 parts. My thinking is, oh I for got I removed the gas tank & it had lots of dried fuel. Looked inside with a scope & my friend did not see any rust, but I could not tell because the dried  gas is rust colored and also stick to the sides. I do think I used a magnet on the dried stuff that came out of the tank & it did not stick to the magnet. My thinking is if I start it now there may be trash still in the tank or fuel lines that will clog up my new injectors & strainer etc... and freshly cleaned upgraded parts. I need to blow out the fuel lines. Or since car seems to be sorta well maintained  many moons ago should I go for it now.
   I am sure I left out other points I want to include but I will pause for now.
Any and all help is extremely wanted & appreciated.
This forum is greatly responsible for me making it this far with my cherished RESCUE/hooptie  ha  ;)
I THANK-YOU ALL GREATLY....... :)  :)  :)
   



« Last Edit: 07 October 2021, 10:41 PM by TNNBENZ »
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Randys01

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Re: Advice Preparing 4 Restart
« Reply #1 on: 07 October 2021, 11:36 PM »

Do I take it that you have bought a new FD and WUR but yet to fit them?
..so we are working with the existent system?
So long as the baffle moves thru it's range without  any hesitation we should be good to go.
Putting anew FD on is not a simple case of plug n play. Combined with a new WUR could be anybody's guess.

Before you start it, disconnect the main fuel feed to the distributor. Disconnect the blue electrical fuel connector on the top of the FD. Turn on the on the ignition: get a jug and collect the fuel. Do this about 5 times to ensure that nothing is coming thru but fuel. All clear? Well then you know that all the back of shop is OK. It generally is...the real nuisance lies ahead!

Remove the fitting in the FD that the fuel feed connects to. There is a small filter....well sometimes there is. Take it out if fitted and reverse clean it. Put it back together.
Now go to the WUR.
Uncouple the feed line and  in the WUR you will see another fine filter. Do what is necessary to clean it....if it need cleaning.

This is not an absolute answer but it it will establish a couple more things for you.

Good luck.

TNNBENZ

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Re: Advice Preparing 4 Restart
« Reply #2 on: 08 October 2021, 09:26 AM »

Do I take it that you have bought a new FD and WUR but yet to fit them?
..so we are working with the existent system?
So long as the baffle moves thru it's range without  any hesitation we should be good to go.
Putting anew FD on is not a simple case of plug n play. Combined with a new WUR could be anybody's guess.

Before you start it, disconnect the main fuel feed to the distributor. Disconnect the blue electrical fuel connector on the top of the FD. Turn on the on the ignition: get a jug and collect the fuel. Do this about 5 times to ensure that nothing is coming thru but fuel. All clear? Well then you know that all the back of shop is OK. It generally is...the real nuisance lies ahead!

Remove the fitting in the FD that the fuel feed connects to. There is a small filter....well sometimes there is. Take it out if fitted and reverse clean it. Put it back together.
Now go to the WUR.
Uncouple the feed line and  in the WUR you will see another fine filter. Do what is necessary to clean it....if it need cleaning.

This is not an absolute answer but it it will establish a couple more things for you.

Good luck.
Much thanks Randy ~~~
   The only NEW parts I have are injectors, Pump, Accumulator, filter, hoses, strainer, wires & plugs, air cleaner/intake seal, probably will  buy injector holders & seals.
I have rebuild kits for cast iron distributor, 1977 WUR,
I found the filter in fuel distributor fitting but do not know how to remove it to clean it !!! 
Your info about running the pump is great to learn... Thank-you
   A big concern is I need a gasket for between the meter housing &  lower meter housing part.  More importantly there was lots of carbon build up & maybe hood insulation present when I removed the metering housing, I cleaned it but am worried what lies below.........   :o  I would like to clean down farther down below but lot of work I think.........
   What about the stuck fuel distributor piston ? Is it ruined ? It appears to be stuck solid...........
I am thinking of using the 1977 parts to just get car started and see if there are any major problems. Then after all rough running issues are HOPEFULLY FIXED. Then install the supposedly improve 1979 parts....... I was hoping to get everything installed now to save having to remove  & reinstall parts........I still may use the 1979 parts I don't know.........ha
The baffle you mention, is that the air metering plate? What baffle are you referring to ?
   I plan to adjust the air plate height properly. Should I lube the roller inside the housing. If so what lube should I use ?
Anyway, keep wishing me luck.......ha
« Last Edit: 08 October 2021, 09:43 AM by TNNBENZ »
Neglected ~ Rescued ~ 1977 450SEL 4.5L  U.S.A. ver.
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rumb

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Re: Advice Preparing 4 Restart
« Reply #3 on: 08 October 2021, 09:42 AM »
You can find plenty of people that have rebuilt their Fuel Distributor and WUR.  I would offer .02 that you send them to http://www.cisflowtech.com/ for rebuild, calibration and testing.  That way they come back fully ready to work properly. These 2 parts are the heart of the system.
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

TNNBENZ

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Re: Advice Preparing 4 Restart
« Reply #4 on: 08 October 2021, 09:57 AM »
You can find plenty of people that have rebuilt their Fuel Distributor and WUR.  I would offer .02 that you send them to http://www.cisflowtech.com/ for rebuild, calibration and testing.  That way they come back fully ready to work properly. These 2 parts are the heart of the system.
Yes rumb.............but I am gonna give it try. I have studied many, many hours, & watched several videos of how to rebuild them...............I cannot afford the rebuild prices........Thank you for the info......... :)
Do you think the stuck fuel piston caused any harm ???  Is it called a piston.........I forgot the proper name..........
« Last Edit: 08 October 2021, 10:32 AM by TNNBENZ »
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Jan S

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Re: Advice Preparing 4 Restart
« Reply #5 on: 08 October 2021, 05:14 PM »
I replaced the entire fuel assembly 7-8 months ago.

I saw some dirt/a bit rust in the tank. To go easy with the new fuel pump I installed a small filter between strainer and pressure damper (before pump inlet). You see the filter to the left in the picture.

Recommended by MercedesSource.

There is not much space for the filter, but with a 90 deg hose nipple I managed to squeeze it in (see pic).
1975-mod W116 450 SE with 6.9 engine

Jan S

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Re: Advice Preparing 4 Restart
« Reply #6 on: 08 October 2021, 05:14 PM »
Sorry, filter at the top
1975-mod W116 450 SE with 6.9 engine

TNNBENZ

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Re: Advice Preparing 4 Restart
« Reply #7 on: 08 October 2021, 10:00 PM »
Great idea Jan.  I watch MercedesSource a lot.  That's Uncle Kenny I was told.......his prices are weird. Your tip helps a lot... Thnak-you  :)
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raueda1

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Re: Advice Preparing 4 Restart
« Reply #8 on: 09 October 2021, 09:16 AM »
You can find plenty of people that have rebuilt their Fuel Distributor and WUR.  I would offer .02 that you send them to http://www.cisflowtech.com/ for rebuild, calibration and testing.  That way they come back fully ready to work properly. These 2 parts are the heart of the system.
Yes rumb.............but I am gonna give it try. I have studied many, many hours, & watched several videos of how to rebuild them...............I cannot afford the rebuild prices........Thank you for the info......... :)
Do you think the stuck fuel piston caused any harm ???  Is it called a piston.........I forgot the proper name..........
A stuck piston is a huge issue. Search the forum for my hydrolock story.  It absolutely MUST move freely and without scratches or flaws either on the piston or cylinder.  It may be stuck because of varnish or gunk from the fuel or rust frrm water in the fuel or both.  Either way, if you can't get it moving freely throughout its travel you're going to need a new one. 

As for FD rebuild, the consensus seems to be that the alloy units are NOT rebuildable, or at least not properly rebuildable,  without a lot of specialized equipment.  Just taking it apart, cleaning and reassembling really isn't a rebuild.  Messing with it will almost certain cause calibration to be disturbed.  To rebuild the iron unit the FD faces must be polished to mirror smoothness.  You'll need a granite grade A surface plate and polishing papers going down to 2000 grit.  3000 is better.  It's a lot of trouble, but necessary.  Keep us posted and good luck!
-Dave
Now:  '76 6.9 Euro
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

TNNBENZ

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Re: Advice Preparing 4 Restart
« Reply #9 on: 09 October 2021, 10:14 PM »
Yes raueda1 I agree .
My cast distributor looks almost new. The alloy one looks good. I have seen many videos on youtube that claim their rebuilds or imply they work. They mentioned your concerns. One suggest a piece of glass & sand paper. I would use crocus paper.  Why do you have to polish & flatten the distributor halves just because you take them apart. They should still be flat if I do not scratch them.
Also the alloy distributor is more sensitive. I do think I may just clean it lightly, will decide later &  revisit youtube.
I never realized a stuck FD plunger could be something other than gummed gas and or rotted plunger seals. I must get them freed without damage, I did know that ! How would you free up the piston ? I was thinking of soaking in a solution. Not sure what solution, cleaning vinegar did an unbelievable job on my screen in the tank !
You want to buy a 1977 Merc ?  :-\ ha  :'(  ha.........
« Last Edit: 09 October 2021, 10:24 PM by TNNBENZ »
Neglected ~ Rescued ~ 1977 450SEL 4.5L  U.S.A. ver.
Project of Compassion ~ Respect
Silver Green Metallic / Toast
Left Hand Drive
Sliding Roof

raueda1

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Re: Advice Preparing 4 Restart
« Reply #10 on: 10 October 2021, 11:16 AM »
Yes raueda1 I agree .
My cast distributor looks almost new. The alloy one looks good. I have seen many videos on youtube that claim their rebuilds or imply they work. They mentioned your concerns. One suggest a piece of glass & sand paper. I would use crocus paper.  Why do you have to polish & flatten the distributor halves just because you take them apart. They should still be flat if I do not scratch them.
You're misunderstanding the nature of the rebuild.  The fact that the piston is stuck suggests that the internals of the FD are anything but almost new.  Have you cracked the cases apart yet?  If not, the you can't base anything on external appearance.  Regardless, if what you're doing is a "rebuild" and you expect it to work properly then the internal surfaces MUST be mirror smooth.  If the FD is used, it isn't new.  Simple as that.  There are tiny orifices inside that need to make perfect surface contact with the steel diaphragm.  I don't know about crocus paper or what the difference is. Regardless, this is the process:

1.   Splitting the unit & Disassembly
1.1.   Remove all the screws and bolt on the underside.  Split the unit.  This can be difficult.   Grip the upper half in a vice and smack the lower half with a plastic hammer.    Once split, you can wiggle the lower half upwards off the metering barrel.   Try to ensure that the central stainless shim stays behind, so that the springs and shims remain securely trapped in the upper half. 
1.2.   Carefully remove the stainless shim.
1.3.   Withdraw the spring seats, springs, and shims from each of the 8 ports.  It is very important that you somehow make note of what goes where, as they MUST all go back in their original places. 
1.4.   Grip the lower portion of the metering barrel in a vice with aluminum jaws, ensuring that you are gripping on the non-working area of the barrel.  You should then be able to wiggle the top of the FD off the barrel.  You will then see the 8 metering slits with rubber o rings.

2.   Internal Cleaning and Refacing
2.1.   The upper and lower halves of the FD may have rust in in places.  You need to clean all this out with small files, pick tools, 800/1500 wet/dry paper etc.
2.2.   Reface the surfaces on the glass.   Make a few light passes with 600 grit first.  If it all looks flat then proceed to the 800, 1500 and 2000.   The mating faces should be mirror smooth.
2.3.   The trick comes with the top half.   Pull out the tiny filters from the output port with a self tapper screw or similar.   When facing the surface, the 8 metering ports MUST touch the wet dry paper.  This will be evident as a change in their color.  Before you start, the metering port tips will be a dull grey.   After the wet dry paper they will go shiny silver.  Each one must be perfect.
2.4.   The upper and lower halves of the FD may have rust in in places.  You need to clean all this out with small files, pick tools, 800/1500 wet/dry paper etc.
 
Also the alloy distributor is more sensitive. I do think I may just clean it lightly, will decide later &  revisit youtube.
Not sure what "clean it lightly" entails....  Regardless, be careful with youtube.  Some videos are excellent, others will destroy what you're working on.  Many offer "shortcuts."  Be highly suspicious of those.  [/quote]

I never realized a stuck FD plunger could be something other than gummed gas and or rotted plunger seals. I must get them freed without damage, I did know that ! How would you free up the piston ? I was thinking of soaking in a solution. Not sure what solution, cleaning vinegar did an unbelievable job on my screen in the tank !
You want to buy a 1977 Merc ?  :-\
Under no circumstances use vinegar.  It's water based and acidic which will promote rust.  Try soaking in paint thinner or using carb cleaner.  Hope all this helps.  Cheers,
-Dave
Now:  '76 6.9 Euro
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

TNNBENZ

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Re: Advice Preparing 4 Restart
« Reply #11 on: 10 October 2021, 12:37 PM »
Thank-you raueda 1 !!!   I was very disappointed that I a have 2 useless FD.  Another forum several members said a stuck piston is hopeless to fix. After much thought I do not believe that.  The main reason is 2 vendors sells rebuild FDs and ask for one in return, ( they rebuid them & resell them ) I do agree that if the insides are to badly rusted they are then junk.  Anyway If my rebuild/clean works I will b ecstatic  ;D  ;D  ;D

You posted : "Regardless, be careful with youtube.  Some videos are excellent, others will destroy what you're working on.  Many offer "shortcuts."  Be highly suspicious of those." I also toatly agree with you.  This is why I try to read all I can & one reason I joined this Forum.
   Thanks to your extremely supportive, & informative replies you have added to my belief that I may be able to reuse my Fuel Distributors.  Just as important you have brightened my spirits from being slightly distraught, to some confidence I might make this work !!!  ;)   :)  ;)
I have both FDs under glass in a stainless steel sink heating in the beaming sun hoping to heat them to loosen & soak up the cleaners I decide to use.  I am thinking of spraying first with brake cleaner, then carb cleaner, and anything else I may think of that might help.  THEN I plan to pour some Marvel Mystery Oil in the recess to soak over night. I think it has nafta ? in it which is a strong cleaner. Oil what you think about WD40 or Rust blaster spray ? Also thought of using a small propane torch to heat up the whole thing..........I am trying very hard to figure out a safe solution.......
THANK-YOU  so very much for your amazing help & support........ :)
Oh I just re-read you directions about how to do this I will try that first before I use a torch.........ha.



« Last Edit: 10 October 2021, 12:47 PM by TNNBENZ »
Neglected ~ Rescued ~ 1977 450SEL 4.5L  U.S.A. ver.
Project of Compassion ~ Respect
Silver Green Metallic / Toast
Left Hand Drive
Sliding Roof

rumb

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Re: Advice Preparing 4 Restart
« Reply #12 on: 11 October 2021, 04:57 PM »
A few random comments.
crocus paper - compared to garnet type sandpapers this is preferable as garnet will embed itself into whatever you are sanding. Wet/Dry sandpapers this is not an issue.

Brake cleaner and carb cleaner are too volatile meaning it evaporates too fast. Find a solvent type cleaner. https://www.kroil.com/ is an excellent penetrating solvent.  I use "solvent" I buy at a local petroleum distributor. You cant buy it much of anywhere else. It's what was used forever in cleaning tanks, now days they are water based solvents.  I have no history using the new stuff, but it should work on everything for cleaning parts. Cleaning tub/sinks and water based solvent is available at Harbor Freight. A good parts cleaner is essential if you are restoring a car.

NO heat, there are orings in there.
'68 250S, '77 6.9 euro, '91 300SE, '98 SL500 '14 CLS550

TNNBENZ

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Re: Advice Preparing 4 Restart
« Reply #13 on: 13 October 2021, 12:29 PM »
Well I started the FD rebuild. I checked to see if all of the small filters in each FD outlet was there. well I lost one.  2 of them came lose earlier moons ago & I luckily found them. One was very lucky to find.  NOW in my haste a few days earlier another one has came out !!!  :-\ I will look but this one could many, many places.........I remember checking last time I found the others I checked to see if the remaining ones were in place securely & they appeared to b secure.   I may have it in another place........It has benn months ago, maybe I found all 3 & just forgot.........
   Anyway are these NLA.  If not how & where do I get more of these worrisome filters.  I read they are not supposed to come out. Is this correct ?
Neglected ~ Rescued ~ 1977 450SEL 4.5L  U.S.A. ver.
Project of Compassion ~ Respect
Silver Green Metallic / Toast
Left Hand Drive
Sliding Roof

TNNBENZ

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Re: Advice Preparing 4 Restart
« Reply #14 on: 13 October 2021, 12:34 PM »
A few random comments.
crocus paper - compared to garnet type sandpapers this is preferable as garnet will embed itself into whatever you are sanding. Wet/Dry sandpapers this is not an issue.

Brake cleaner and carb cleaner are too volatile meaning it evaporates too fast. Find a solvent type cleaner. https://www.kroil.com/ is an excellent penetrating solvent.  I use "solvent" I buy at a local petroleum distributor. You cant buy it much of anywhere else. It's what was used forever in cleaning tanks, now days they are water based solvents.  I have no history using the new stuff, but it should work on everything for cleaning parts. Cleaning tub/sinks and water based solvent is available at Harbor Freight. A good parts cleaner is essential if you are restoring a car.

NO heat, there are orings in there.
Neglected ~ Rescued ~ 1977 450SEL 4.5L  U.S.A. ver.
Project of Compassion ~ Respect
Silver Green Metallic / Toast
Left Hand Drive
Sliding Roof