Neighbor has an 84 300TD

[Fordsandguns]

My dads neighbor recently got an 84 300 TD. The return line on the rear cylinder has been plugged off for some odd reason and all the return likes are leaking. He knows nothing about diesels so he asked me for help.
I have no experience with MB's. Is the plugged line supposed to run straight back to the tank as it seems or does it go to the ip?
What size are the lines and are they supposed to have clamps? None of them do if they are supposed to.
Thanks in advance for any help.

On Edit: It's actually an 83 if that makes any difference.

 

[1994Diesel]

I though it was odd that mine was plugged off too, but its how they came from factory.

 

[The Warden]

Like Justin said, that plug on the end of the line coming off the #5 cylinder is factory and is supposed to be that way. Basically, the hoses are connecting the injectors in a daisy-chain pattern, with the line off the forward part of the #1 injector going to the fitting on top of the cannister-type fuel filter (the fitting has a banjo bolt going through it, and also serves as the part the fuel filter threads on to). No clamps are needed; if you use the proper line, it will be a very snug fit. Using the proper line, I've never had a hose pop off, although I did have an incorrect hose come off once.

Easy job to replace This is the hose you need, although I think you'll want to order two of them...I THINK 22 inches will be enough to do the job, but I'm pretty sure 11 inches isn't enough...

 

[1994Diesel]

Like Justin said, that plug on the end of the line coming off the #5 cylinder is factory and is supposed to be that way. Basically, the hoses are connecting the injectors in a daisy-chain pattern, with the line off the forward part of the #1 injector going to the fitting on top of the cannister-type fuel filter (the fitting has a banjo bolt going through it, and also serves as the part the fuel filter threads on to). No clamps are needed; if you use the proper line, it will be a very snug fit. Using the proper line, I've never had a hose pop off, although I did have an incorrect hose come off once.

Easy job to replace This is the hose you need, although I think you'll want to order two of them...I THINK 22 inches will be enough to do the job, but I'm pretty sure 11 inches isn't enough...

I had one pop off too, not nearly as much fuel is comming out of there as one thinks. A different animal than international IDIs.

 

[Fordsandguns]

Like Justin said, that plug on the end of the line coming off the #5 cylinder is factory and is supposed to be that way. Basically, the hoses are connecting the injectors in a daisy-chain pattern, with the line off the forward part of the #1 injector going to the fitting on top of the cannister-type fuel filter (the fitting has a banjo bolt going through it, and also serves as the part the fuel filter threads on to). No clamps are needed; if you use the proper line, it will be a very snug fit. Using the proper line, I've never had a hose pop off, although I did have an incorrect hose come off once.

Easy job to replace This is the hose you need, although I think you'll want to order two of them...I THINK 22 inches will be enough to do the job, but I'm pretty sure 11 inches isn't enough...

Thank you. That is an odd looking setup when you are used to an IH idi!
I haven't ridden in it yet but he complains about how slow it is. I know these weren't speed demons but what kind of acceleration should be expected out of it?
I am interested just because it's a diesel but also because he doesn't really like it and has mentioned maybe selling it.
If and when that time comes I will get it if I can.
It's in decent shape and would make a cheaper alternative to the CC.

 

[Fordsandguns]

A friend of mine just bought an 84 300td (why I said the first one was an 84 I guess) for $500. Running , tagged and inspected.
I'm jealous!

 

[1994Diesel]

A friend of mine just bought an 84 300td (why I said the first one was an 84 I guess) for $500. Running , tagged and inspected.
I'm jealous!

Wow 500 for a running car is a steal! I bought my 76 for 600 not running!

 

[The Warden]

FYI, that picture's actually of a 300D...the "T" in "300TD" doesn't stand for "Turbo" like one would think it actually stands for "Touring" or the German equivalent thereof, and was M-B's designation for a station wagon. A 300D is a sedan; a 300TD is a wagon, and a 300CD is a coupe.

They are most certainly NOT speed demons...I don't recall the exact "specification" 0-60 time, but I want to say that it's in the realm of 15 to 20 seconds. With that said, there are a few things worth looking at...first, with the engine off, have someone put the accelerator pedal to the floor and take a look at where the linkage connects to the injector pump, and see if you're getting full throttle. After about a year with my first 300D, I found that with the pedal all the way down, I had about 1/8" before the linkage was actually maxed out...I adjusted the linkage, and the difference was night-and-day.

A couple of other things...first, don't be afraid to do a WOT acceleration. These engines were designed to be driven by taxicab drivers with binary right feet and the engine actually isn't happy unless it's given regular full-throttle accelerations. Also, the injectors could be dirty...they can be replaced, but I would start out by running a full-scale Lubro Moly Diesel-Purge treatment through the fuel system, and see what that does. Doing a valve adjustment would also be a good idea. Lastly, run a few Italian tune-ups to make sure that the mufflers (yes, there are two ) are clear...when these cars are being driven like they're owned by my grandmother, the soot tends to clog the mufflers, and the best way to clear them out is to do a few full-throttle high-speed runs

Hope this helps some ...BTW, IIRC the GM 6.2l and 6.5l has a similar injector return line setup to the M-B's, and I think that it's actually a better design than what our IDI's use...less of a chance of air intrusion...

 

[Fordsandguns]

Thanks! See, I told ya I didn't know anything about MB's!
Ok, the pic was sent to me, I haven't seen it in person yet.
And I guess I remember the 300TD wrong on the neighbors car as it is a sedan. I thought for sure it said 300TD on the trunk. Oh well, either way it's worth having. But the wagon would be even better I think.
I'll direct him to the return hose and checkout the throttle as you suggested.
Talking him into the diesel purge might be a little harder, but I'll tell him.
He does drive it like a grandpa, though he hasn't had it long enough to clog up the mufflers himself.

Most of the older generation here drives diesels like they'll break if taken over 1200 and the younger generation thinks the only diesel worth having is a cummins and that it must be driven like a ferrari!

 

[The Warden]

Thanks! See, I told ya I didn't know anything about MB's!
Ok, the pic was sent to me, I haven't seen it in person yet.
And I guess I remember the 300TD wrong on the neighbors car as it is a sedan. I thought for sure it said 300TD on the trunk. Oh well, either way it's worth having. But the wagon would be even better I think.
I'll direct him to the return hose and checkout the throttle as you suggested.
Talking him into the diesel purge might be a little harder, but I'll tell him.
He does drive it like a grandpa, though he hasn't had it long enough to clog up the mufflers himself.

No worries; I made that mistake myself at first. And, it's possible that he (or a previous owner) DID put a "300TD" badge on the car; just, it's good to know what you're actually dealing with. Assuming it's a standard U.S. market car, it SHOULD be a chassis W123.133...might be a good thing to know. If you haven't already, take a look at this thread. The Diesel Purge should really help with cleaning up the fuel system, and on the same note, it would be worthwhile to replace both fuel filters (there's an inline filter just outboard of the IP that goes into a hand primer pump, and there's the spin-on filter just behind the power steering pump reservoir and the cruise-control actuator). FWIW there's also a fuel strainer in the bottom of the fuel tank, that the suction line goes into...algae can be a serious problem on these cars and there's a very real chance that this strainer's at least partially plugged up. With an empty tank, pulling it and cleaning it isn't that difficult...replacements aren't hideously expensive, but they're generally not bad enough to warrant replacement. And, for reasons I'll go into below, you may want to try and get him out of the habit of driving like a grandpa...I'm generally a conservative driver, but with these cars (and, really, any European diesel), driving too conservatively is bad for the engine.

Most of the older generation here drives diesels like they'll break if taken over 1200 and the younger generation thinks the only diesel worth having is a cummins and that it must be driven like a ferrari!

Sounds about right I used to be guilty of the former "offense" in spite of being relatively young (was "raised" on low-revving marine diesels), but the European diesels are a completely different animal. The engines have considerably less rotating mass, and the valvetrains and rotating assemblies are designed for considerably higher RPM's. Our IDI'***** the governor at 3400 RPM and you want to be cruising in the 1700 to 2000 RPM range, but the OM617's governor's set at 5500 RPM and you're actually lugging it at anything below about 2500 RPM. dyoung would have a field day

 

[Fordsandguns]

Given a 5500 governor dyoung would want 7000!
Thanks for all the advice, I do appreciate it.
I had already told him to get a new filter but I didn't know about the second one.
I'll pass along the info to my friend too. He is actually a member here (91fummins) but doesn't get on here often.
he is planning on giving his MB to his sister so he'll be happy to get knowledgeable advice as he wants it to be reliable for her.

We were joking about converting one of these to a stick with a t5 from a mustang.
I wonder how the gearing would work on that with the higher rpms available with the euro style engine.
Just fun thinking.