Mercedes diesel injector SHIM related data
 

Don't waste your time and money attempting this DIY without an Injector Pop Tester!!!
http://www.peachparts.com/shopforum/diesel-discussion/170935-injector-pop-tester-generic-instructions.html

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These sizes are a Must have for adjusting "pop" pressure on diesel injectors.

I strongly suggest you have ten each, in hand before beginning:

11.4 mm outside diameter x 0.13mm shim washers (approx 10 PSI each)

11.4 mm outside diameter x 0.16mm shim washers (approx 15 PSI each)

11.4 mm outside diameter x 0.21mm shim washers (approx 20 PSI each)

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All Mercedes (BOSCH) 1961 to 1995 OM615, 616, 617, 601, 602, 603 engine injector shims have the same 11.4 mm outside diameter.
They can be used on other BOSCH diesel injectors besides Mercedes, which use the old indirect mechanical injectors.

The key is using more than one shim to meet the total thickness requirement.
Using a thick shim (typically found in your injector) with 1 to 3 of these thin shims you can make (almost) any required thickness for correct "pop" pressure.


Mercedes diesel injector shim related threads

http://www.peachparts.com/shopforum/diesel-discussion/299321-diesel-injector-cleaning-diy.html
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http://www.peachparts.com/shopforum/diesel-discussion/311856-injector-shims-sources.html
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http://www.peachparts.com/shopforum/diesel-discussion/261796-injector-shim-sizing.html
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http://www.peachparts.com/shopforum/diesel-discussion/219165-injector-shims.html
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http://www.peachparts.com/shopforum/diy-links-parts-category/142405-diesel-injection.html
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Injector Shimming and Calibration - TDIClub Forums
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Injector + Heat shield + Nozzle, Prechamber + Collar, and Nailing. LINK THREAD
http://www.peachparts.com/shopforum/diesel-discussion/211750-injector-heat-shield-nozzle-prechamber-collar-nailing-link-thread.html

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I just sanded (2000 grit) the mating surfaces until i got to the desired opening pressure. Extra shims are a waste imho.

... I understand this will reduce spacing, but isn't there a limit to the usefulness of this trick? I'd not want to lap off, .25mm from the body...
and what do you do if the pressure is too high? remove a shim and lap some more?

You can do that but keep in mind that you are doing it for yourself. If you were doing this on the Job the cost of paying someone to lap the surfaces out ways the time spent swapping shims.
If some one is left a lone to rebuild the Injectors as a whole set and has the right equpment and parts (includinga selection of Shims/Spacers) it takes only 10-15 minutes per Injector to rebuild them. Shops used to charge for 1/2 Hour of their labor rate to rebuild the Injectors.

If for some reason you get lucky and most of the Injectors you assemble have good opening Pressures the time can be less per Injector

Yes, if you lap off too much from the upper face of that intermediate Plate the Lower Spring Seat will rest on that plate instead of the top of the Nozzle Pintel.
However, I have never seen that happen before.

Hmm
 

How much time for cleaning the exterior injector body?
From personal experience, I plan 0.25 - 0.45 hour per injector = depending upon how nasty (corroded) the exterior is..

.

Like I said the Charge was for 30 Minutes per each Injector. Normally that was an easy time to beat. Once in a while you come a crossed that one problem injector that you have an issue getting the opening pressure on if it uses Shims and spacers that throws your time off.

But, we often soaked stuff in the Old Style Carburetor Dip. While it is soaking you just do something else so you don't lose time waiting on it to eat up the Carbon and grease.
We usually only used the Ultra Sonic Tank on DI Injector Nozzles. But that is another throw them in the Tank and go do something else thing.

If you keep all of the Parts from one Injector together the Opening/Pop Pressure will often be close to what you want and that can cut down on the number times you have take apart and re-shim the Injector.

The Fuel Injection Shop was well equipped. I did not have to look for any Tools because they were all behind Me hanging on a Board.
The Bench was in front of and about 10 feet long with a Vice with Copper Jaws in the Middle.
The Bench had Filtered Compressed Air

Where I worked had a big Motor with a 12 inch fine Wire Wheel mounted on it. That is what I used to clean the exteriors of the Injector Body.
If really corroded we had a course wire wheel.
For something extremely bad we had a Glass Bead Blaster.

Remember I was in S California back then and now. Not a lot of People owned Mercedes back then and due to the Weather in my area they were not likely to be severely corroded.

The other Injectors we got were from Commercial Vehicles where how the looked was not as important as the Cost to rebuild them. So if the bluing was a little patchy it did not matter.

We had filtered compressed Air and Air Guns with different sized Needle ends on them to quickly blow out tiny passages.

We did have some Cold Bluing that could be applied but that was not routine. The Cold Bluing was mostly reserved for Detroit Diesel Injectors and sometimes the Cumins Injectors.

Depending on the Injectors some of the Parts could go on the Lapping Machine.
On Mercedes Injectors both sides of the Center Plate can be lapped on the Machine; all of them can be done at the same time.

I generally lapped the upper body by Hand.

We used 500 Grit Lapping Compound. I have read that some People disagree with that but I know it worked for the 5 years I worked in that shop.
We used the same to lap the tops of the Elements and the bottoms of the Delivery Valves when we a Fuel Injection pump was overhauled.

If you need to take an Injector apart to change the Shims you measure the shim Pack or Shims and measure what you put in. Note the Pop Pressure you got and from there you now have a formula for that Injector and if you have to change the opening pressure you know how man thousands of an inch you need to change when you select another Shim.
If you have a good selection of Shims you will only take the Injector apart one more time.

That is part of what I can remember about doing the Job.

Rebuilding Injectors is the job that they start the New People out on.

Hmm
 

I wish corrosion was not a major factor in my area.

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I took mine from 1900psi to 2100psi with about 1 minute of sanding. It doesn't take much.

There is a really large difference between "PSI" and bar. I think you are mistaken.

e300 e300d om606 injector shims are 9.8mm x 3.0mm

I believe most of the info on Injectors is not from 606.*** Engines.

If the 606.*** Engine Service Manual is the same as the 617.952 and older Engines then there is a spec in the Manual that gives the aproximate amount of bar change results from a certain thicknes of Shim.

I am going to rebuild my injectors soon in my 617. What pressure are they supposed to pop at? I do not have bar on my gauge only psi. At this point I do not have any shims where is the best place to get some? If I do sand one person mentioned 500 grit lapping compond what grit sandpaper would you use 1000-2000? What part of the insides would you sand? How do you know if your injector is no longer any good and needs to be replaced?

A non turbo is a 617.91x a turbo engine is 617.95x, hope this helps.

You need proper pressure and a good spray pattern. You can use shims to get the pressure right and if you have a bad spray pattern, replace the nozzles.

Once you have the injector apart, lap the mating surfaces, this helps in sealing the two halves when reconstructed. Item number 5 & 7 in last pic.

1950 psig. Best they can probably be trimmed is +/-50 psig.
Lookup my post. I gave McMaster-Carr PN's for steel shim washers that worked for me. As I recall, 0.1 mm shim gave a 100 psi increase. I never lapped the parts and never had leaks (both cars).

I suspect that spray pattern and lack of dribbling is more important than pop pressure. I say this because I found 3 of 5 injectors in my 1984 300D popped at 1600 psig and were for a non-turbo engine, yet changing them made no noticeable difference.

Fuel seems to make a big difference. I run Diesel HPR (only in CA) and when idling at a stoplight, the other cars can barely tell I have a diesel, with their windows down. It sounds as quiet as the newer M-B CDI diesels.

Recheck this on the internet. 1 bar= 14.5 psi.

I am the one that said where I worked in a fuel injection shop they used 500 grit.
I personally used 600 grit when I rebuilt my injectors as that is what was available on ebay at a decent price. I used a plate of glass as a lapping plate. (Later I bought a real lapping plate but have not needed to use it.)

You can get the lapping compound on eBay, I believe what I bought was aluminum oxide. People that polish Rocks as a hobby use it.

FWIW I have been told by a very experienced MB mechanic that the 135 bar injectors were used on NA engines too, it's just that the turbo engines took over in USA with them so folks over there assume NA engines stuck with 115 bar ones.

This was so easy I'm wondering if it will work:
 

McMaster-Carr
404-346-7000
404-349-9091 (fax)
atl.sales@mcmaster.com
Receipt
Billed to

Mcmasters-Carr

Line Product Ordered Shipped Balance Price Total
1 98055A105 Spring Steel Round Shim, 0.1MM Thick, 6MM ID, 12MM OD, Packs of 50 1
Pack
1 0 5.69
Per Pack
5.69

2 98055A106 Spring Steel Round Shim, 0.2MM Thick, 6MM ID, 12MM OD, Packs of 50 1
Pack
1 0 5.17
Per Pack
5.17

3 98055A107 Spring Steel Round Shim, 0.3MM Thick, 6MM ID, 12MM OD, Packs of 50 1
Pack
1 0 5.86
Per Pack
5.86

It would be nice if there was some printed material to back that up. After all the Mercedes Service Manual has NA and Turboed Engines and as far as I know it lists the opening pressres as being different.

I believe that difference in opening pressures is also the same if you look and other makes like VW and Volvo diesels comparing the turboed to NA Engines.

Clemson the shims you got from mcmaster were 12 mm o.d. the shims hunter recommended were 11.4 o.d. yes will the ones you got fit? Did anyone use these shims from mcmaster yet? I want to do my soon and want to have the parts on hand before starting.

If I'm not mistaken Bill installed those shims years ago.

So, how bout it, Bill?

"BillGrissom BillGrissom is offline
Registered User

Join Date: Aug 2010
Location: Sacramento, CA
Posts: 1,252
1950 psig. Best they can probably be trimmed is +/-50 psig.
Lookup my post. I gave McMaster-Carr PN's for steel shim washers that worked for me. As I recall, 0.1 mm shim gave a 100 psi increase. I never lapped the parts and never had leaks (both cars).

I suspect that spray pattern and lack of dribbling is more important than pop pressure. I say this because I found 3 of 5 injectors in my 1984 300D popped at 1600 psig and were for a non-turbo engine, yet changing them made no noticeable difference.

Fuel seems to make a big difference. I run Diesel HPR (only in CA) and when idling at a stoplight, the other cars can barely tell I have a diesel, with their windows down. It sounds as quiet as the newer M-B CDI diesels."
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Let me know if you want a handful of those. I have fifty of each of those three items.

Dan

Clemson 88 I pm'd you on the shims. Don

Sure, just search for my post of several years ago (searching from Google works better for me). As I recall, I only used one 0.1 mm shim, and only in a few injectors to tweak the pop pressure up ~100 psi. I have probably pop-tested 3 sets so far, for my cars only. See my post on my pop-tester w/ electronic recording. I recall the M-C shims are slightly smaller OD than the spring, but will still touch it everywhere if offset, and sounds like even larger OD than the "correct" shims.

I may re-pop some in 5 years or so, which might tell if the shims wore, so wait for that if really concerned. Otherwise, not risking much if you buy a few bags from M-C, and probably only need the thinnest ones they carry.

And don't PM me asking to buy some of mine (like one guy). Too much trouble to dig the stuff up and mailing would cost as much anyway. M-C takes a credit card, and you can find much stuff there for your other projects. Note they carry the special 6 mm adapter fitting you need to connect a home-made pop-tester to a M-B fuel tube (don't PM me for the PN, lookup my post).

Thanks, Bill.

I posted my order from Mc-Carr above. I'm good and it's good to know that those shims worked. I'm sure many of the members here will purchase those instead of those sold by Diesel Gnat.

Hi,
My name is David, from France and new to this forum.

WHUNTER mentionned 11,4mm shims diameter for Bosch injectors but when I contacted Mercedesource, they only sell 11,5mm shims, 0,1mm larger...

I need some 11,4 shims for my Lucas injectors on a Renault Clio. And I can't find any, only 11,5mm...

Can I have some advices ?
Thank you

Shim : https://photos.app.goo.gl/86H9SOJiz64t9YDk2

I was unable to find injector shims for my 1995 e300. The shims are good for 1995 - 1997 injectors.
Well I bought a die and some shim stock and made my own.
I'm wondering if anyone else has had trouble locating these shims.
I called a local diesel injection shop and Bosch sells the shims but you must buy 10 of each size. The sizes run something like 8.1 mm, 8.2 mm, 8.3 mm and so on. They run like $5.00 each.
I didn't want to go this route. So I bought a die to produce a shim of .375 od and .125 Id in the following sizes .0035, .005, .006, .007, .009 inches.
My local diesel injection shop manager said that every .1 mm gains approximately 100 psi. .1 mm is approximately .004 inches. All my injectors were 200 psi low. So I needed approximately .008 to get to 1668 psi. Keep in mind that a little tweeting is required to get the desired setting.
PM me if anyone is interested in some shims.
Like I said... these are almost impossible to find. I did hear that the shims were a dealer only part but the dealer doesn't sell them anymore.
Roddy



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So I found out that the 98 - 99 e300 use the same injector but the pop pressure for the turbo engines is 135 bar or 1958 psi.
So the shims will work for 95 through 99 mercedes e300.
Roddy

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I just finished
adjusting my 1995 e300 injectors. Found out that for every. 001 the pressure goes up 40 psi. All my injectors were 200 psi low so I used .005 inch shims and got to around 1668 psi or 115 bar.
At first I put in a .009 shim and got around 1950 psi.
I wasn't expecting that because I've been told that every. 004 would increase the pressure by 100 psi. That equals 25 psi per .001 shim. That is a figure that works on the 617 engines. While the 606 engine injectors respond quite differently. For every. 001 the pressure increases 40 psi. So when I bought my shim stock I bought shims in excess of .005. I now know to buy much thinner shims for the 606 injectors.
Roddy

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Just got my e300 running again. Cranked it two times with the fuel feed opened up all the way and noticed a bit of fuel on the injector line going to the injectors. Tightened the injection lines and it started right up.
My car used to smoke a bit but that has stopped. The engine is more responsive and starts better.
I did re time the injection pump to 13.5 after top dead center. Seems to have made a slight difference. Idle is nice and smooth.
Roddy

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Not injector related but since I adjusted the injectors pop pressure the return line going from number 1 injector to the main fuel filter keeps popping off and spraying fuel everywhere. I made a note on another thread. Bottom line the 1 way valve going from the main fuel filter to the hard line return line was installed backwards. I blew some compressed air through the hose connected to the hard return line and heard a bubbling sound coming from the fuel tank. Took the fuel cap off first. That told me there wasn't a blockage down stream. Just in case this happens to anyone else.
Very hard to believe someone would install a 1 way valve backwards.


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