I am new to the forum, but have had my 1984 300D Turbo for about 4 months. I am changing ALL of my injectors, as I have read the posts and it seems like the thing to do. Weak power and nailing slightly.
Now, I will need a step by step procedure, clear and concise, as to how about getting this done. I have the tools, torque wrench, 27mm deep well socket, etc. I gleaned this info from other posts also.
I need to know about heat shields, which way do they go in.
I need to know how to remove the old heat shield.
I need to know how to install new heat shield. Do they drop in, thread in, press in??
I know my work area must be CLEAN.
I know the torque specs, and have converted them to ft/lbs.
I know not to loosen the lines @ the IP.
I know to replace the overflow lines.

And, just any tricks or whatever to insure all goes well.

Did you check the DIY of BoostnBenz? I have searched his postings many times for info.

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Steve
'87 300TD - 132K - Soon 4-Sale
'84 300D Turbo - 122K - Driving
'77 VW Type II - 77K - Restored
'08 250EX Ninja
English Bulldog (Brier) - My best friend. Passed away 12/02/04 while in my arms.

I did check the DIY pages. Great info, but not about injector replacements..

Injector's are simple to replace, first don't buy rebuilt ones. Take your old ones to a good injector shop and have them gone threw. Since most of the new ones are junk out of the box if you do buy new ones take them to a shop just the same and have their pop pressure and spray pattern checked. (I am talking from expereance I already spent $300+ on rebuilt injectors and still need to get them checked )

Ok first clean the area, keep everything clean, no dirt, crap or oil should be around them.

Second pull the old injectors, their in their real tight so put your back into it

As far as the heat sheilds are concerned they are just a metal crush washer/spacer. You will see them when you pull the injectors out, I used a screw driver to get mine out. Just match what is in their when you get yours out. One my 603 the tapperd end goes down.

The new heat sheilds will drop right in, you will see when you get them out.

If you can change spark plugs you can do injectors, a very simple job.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Just what I was looking for!!! I read many threads about the injector and that the shields should be replace. But, I also saw where someone used a slide hammer/dent puller to remove the old ones. Sads bad to be doing that inside a cylinder...

th' precombustion chamber(with th' correct adaptor) AFTER th' removal of th' injector. Th' heat shield most likely will stay down in th' chamber & have to be wiggled loose(mine was stuck pretty tight). I don't think th' heat shield is a crush washer. It is cut to fit th' bottom of th' injector and is obvious as to how it is to be oriented.

Thank all of you very much. If I understand correctly, the heat shield is installed with the concave side towards the injector, and the convex side towards the piston. I will be installing my new injectors and shields tomorrow morning. Hoping all goes well. And again, many thanks to those who have taken their time and knowledge to educate me.

Wasn't there some discussion a while back about reaming out the precombustion chambers when changing glow plugs?

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Alan Hamm
'87 300SDL 277K Miles
'89 560 SL 68K Miles

http://skinnerbox.steaky.org/Service/W123/w123CD2/Program/Engine/617/07_1-137.pdf

Read this first even if you are replacing them instead of cleaning yours. It's the factory manual on how to remove, disassemble, clean, reassemble and install injectors and heat shields.

I shot my pre chambers with a little carb cleaner, but they looked good. When you get the injectors out you will see the heat sheild, it is simpler to look and see then for us to try to explain.


Compare an old heat sheild to a new one, they do crush a little, you are making a tight seal. Thats why everything has to be very clean!

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Why is it a problem if you remove the lines at the IP ? I removed the intake plenum on our 3.5 to clean out the soot and grunge buildup, and it also looks like it makes changing the glow plugs much easier.

There is no problems accociated with removing the lines at the IP AFAIK, and I've done it on dozens of different engines. Be sure to cover the exposed ports with blue painter tape or a lint free cloth to avoid particulate intrusion.

Timely thread. I'm about to do this, too!

Where does one get the heat shields? Do they normally come with new injectors, or do they have to be purchased separately?

So is it really a bad idea to purchase new injectors? Am I better off getting my existing injectors tested/rebuilt? This is my only car, so I can't handle a lot of downtime waiting for injectors to get rebuilt.

Thanks!

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'81 300TD turbo <<sold 12/05 to another diesel nut

I would get the new injectors tested anyway. If you can't let the car go down buy new ones and have them checked. The heat shields have to be purchased separately, but they are cheap.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

The injection place I go to will usually do am-in/pm-out work on the injectors. heck, one time they weren't real busy and they pop tested them while I waited. Check with the shop in your area that does everything from pickup truck engine to over-the-road diesels. I use Diesel Injection Service in Cincinnati.