Hello All, I'm having problems with my injectors. Or getting the right injector. The car is a 79 NA 300D 90k miles. After getting the car I
did a valve adjustment and cleaned the injectors. I cracked the lower
housing on one taking it apart but its only in the hex area. This injector
now gets soot after driving a hundred miles or so and the car starts to
run worse. I have tried 2x getting a new injector but they don't match
the other 4 and both nail. I did not get them here at our site. I didn't
want to send back the cracked one as a core. Any advice is welcome
and needed. You can see the difference in the pic if it loads. Thanks

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Greazzer on here is Da Man for MB injector questions. He built the injectors for my race engine and is honorable and does what he says he will. I'd PM him (if he doesn't check in on this thread) and see what he has to say. I could offer my experience with my race engine but that really wouldn't be much help to you.

Dan

I had been in touch with him last month but didn't want to send
the injector with the cracked housing and some other work
got in the way.

The 2 replacements I have gotten don't match. I don't know
if they belong to a turbo motor? The engine does not like
them.

I'm going to call Pelican and see if they can point me in the right
direction. I don't want to give up on the car as all else is very
nice with it but this is getting frustrating.

If you look at each injector, you will see a number stamped into the body. It will be either 115 or 135. That is the fuel pressure at which the injector will fire.

Assuming your '79 still has its original NA engine, all your injectors must be 115. The car won't run properly if they are mixed.

You did install new crush washers (aka heat shields) when you replaced the injectors?

The injectors you say you got... New? Used? If new and you didn't buy them from someone who specializes in parts for these cars, their parts catalog might not list the correct non-turbo fitment anymore. Plus some commercial rebuilders don't set the opening pressures with great accuracy.

Also, how far have you driven the car since you put the "new" injectors in? It isn't unusual for rebuilt injectors to be very noisy for a while.

If you want to do this properly, I suggest you put a "want to buy (WTB)" ad in the classifieds subforum here, asking to buy a complete set of non-turbo injector as cores. Send those to Greazzer and let him either clean or rebuild them, as needed, and set up the correct opening pressures, all nicely balanced across the five. That's what I did.

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

There's your answer! Love this forum. Sorry I couldn't be of much help.

Dan

Thanks for the input. I must have did something right because the other
4 are firing good. I can't put new heat shields in every time chasing this.
I'm asking what is \ what are the difference in these \ and why I can't
order a matching injector. Why do my existing injectors have a shorter
barrel than what I have gotten 2 x online? Call to Pelican did not help.

Why can't I buy a matching injector? You guys are missing the point.
Even pelican sales said watch this post.... They don't know ?????

Here's another thought. You could contact Dieselmeken in Sweden - he did my pump. If he doesn't have access to the right injector (send him the "115" marking info) I'll bet he can tell you who does.

Warning - he speaks and writes Swedlish but really his English skills are pretty good. Be prepared that he may not get your question the first time. I think he augments correspondence from English-speaking customers by running it thru a translator and those are sometimes off a peg or two.

Dan

I'm think I'm done with it, part the old girl out

I did not read all of the posts so this could be a duplicate.

You can use either of the types of Injectors on your vehicle if they Pop Pressure is set for your Engine. However, the parts inside of the different Injectors are also different and you cannot interchange the parts.

Speaking of a used Injector:
When that long injector nut cracks you can exchange it for another one without changing the Pop Pressure. However, when you do that you give crap a chance to get between the lapped surfaces and even if you get it put back together without any thing getting in between the lapped surfaces there a small possibility the lapped surfaces will not seal.

Simply keep all the parts from one Injector together.

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84 300D, 82 Volvo 244Gl Diesel

No idea how you could tell that 4 of the 5 are "firing good". The main way is a "power balance" as long done w/ gas engines w/ spark wires. Disable each cylinder one at a time by cracking the top injector nut until it seeps fuel. See if each cylinder has the same effect on idle.

Could be some of your injectors are even for non M-B. Seems Bosch diesel injectors of similar vintage are almost the same for VW, Volvo, etc cars & trucks, but check Google Images. Main thing is that the pop pressures are about the same. The injection pump determines the volume flow to each cylinder.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

The Injector bodies from My Volvo D24 Diesel are the same as the VW Rabbit and they worked on the Mercedes. The first time I rebuilt the Injectors for the Mercedes with brand X type Nozzles I used VW Rabbit Injector Bodies.

The difference is that the Mercedes Injector Bodies have a metal Edge Filter inserted into the Injector Inlet.

The metal edge filter is item 13 in the diagram.

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84 300D, 82 Volvo 244Gl Diesel

for a relatively simple problem such as injectors if the rest of the car is reasonably good. You got some good advice here. The best of it may be to pull all of your injectors and send everything to greazzer. You will be pleased with the result and won't have to sell your kids into slavery to pay for it.

I've found a correct set I hope. Thanks for all
Of the advice.

Note that on Bosch rebuilt Injectors they cover up the info stamped on the Injector Upper Body so that they can use it to build what ever they want the Injector for. The cover up is done with a plastic band that has the Number of the Injector that they built.

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84 300D, 82 Volvo 244Gl Diesel