Sounds like air in the system. Sometimes, slightly cracking loose the injector lines, while running, and listening for a stumbling then retightening for smooth out will bleed air from the system.

You didn't mention changing fuel filters. Is the small primary filter clear and full of fuel with no evidence of black?

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Sam

84 300SD 350K+ miles ( Blue Belle )

I don't doubt this diagnosis at all. I have had repeated trouble with air in the lines, as I am new to bleeding the fuel system...well, I'm new to all this. But an unprimed fuel system was the reason I couldn't get it started after the valve adjustment. I did crack the injector lines until it stumbled, one at a time down the line, and that helped, but it's been a while since I've done this.

Also, to your question on the clear fuel filter, ever since I replaced the small fuel filter, it's definitely had air in it...I thought this was normal to have a pocket of air near the top and couldn't get rid of it when I tried. It's run with that air for months, so I assumed that wasn't a problem. Could that pocket of air cause it to do this, and if so how do I get rid of that air?

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1980 300SD Turbo Diesel
"Bailey's. Mmm...creamy. Soft, creamy beige." - Old Gregg

The air in the clear fuel filter is normal. I think they were just making sure that fuel filter wasn't full of dark gunk which you would be able to see, as that could clog the filter and prevent it from flowing the necessary fuel. As long as it's still clear and clean, it should be good.

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1984 Mercedes-Benz 300D

I understand the cams themselves are not as well built as 81 and above ,if the lobes are extra worn its a problem .

Ok, no it's not full of dark gunk, though I haven't looked at it very closely. Two other possibly relevant points:
1) I did a diesel purge with LubriMoly before I reinstalled the injectors, and didn't change the fuel filters then. I know some recommend it, but others said don't change it unless it needs it...I'm not sure how to tell.
2) I do have a fuel leak - the braided section of hose between the fuel tank and the hard fuel lines will be totally wet after seconds of the engine on, and it's actually dripping once the engine has run for a bit. Yes, I need to fix that, and it's an easy fix...but could that have anything to do with this?

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1980 300SD Turbo Diesel
"Bailey's. Mmm...creamy. Soft, creamy beige." - Old Gregg

2. Change the fuel line with a piece of 5/16" hose. The lift pump is pulling fuel from the tank, and could be sucking in some air.


If you still have the original line, it will have a crimp on end at the tank. Be sure you are on the reserve, then you will have 3 or less gallon of fuel. Place a small pair of Vice Grips on the hose, remove it from the fuel pipe. point the hose in a 5 gal bucket and remove the VG.

The crimped on end screws into the fuel tank screen. think it is a 19mm wrench to remove the hose, or cut it off and use a deep socket. cut down the sides of the crimp with a Dremmel. the fitting that screws into the tank will have a barb end. then slip on the 5/16" hose and you are good.

The fuel tank screen uses a 46mm or a 1 13/16 socket.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

love your screen name! i rode a white 84 bitd.

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1982 300sd from craigslist $800 greased on one tank with NO CONVERSION in the Hot Texas Sun. (currently dead & awaiting engine damage investigation and/or longblock swap)
new daily: '03 vw 5speed jetta tdi wagon. bagged&chipped

Update:

Repeated the valve adjustment again this morning. Went much smoother than my first time! I think my biggest issue was that I wasn't holding the spring retainer in place, so even after I got the clearance correct, when I tightened it back up the spring was turning too and it was somehow throwing off the clearance. This time, tho I still don't have that 3rd wrench, I was able to hold it in place with a screwdriver wedged in there or with a set of pliers.

Anyways, here were the clearances - last time first and then today:
1e) .33 - .33
1i) .10 - .075
2i) <.05 - .075
2e) .33 - .35
3e) .35 - .35
3i) .065 - .10
4i) .065 - .075
4e) .23 - .35
5e) .33 - .33
5i) .10 - .065

Is it possible that they changed that much in just 4-6 months time? Before that, no telling how long it'd been.

I then started it up, bled the fuel lines by cracking the injector lines at the injector (sure enough at least some air did come out - bubbles), and it's sounding and starting pretty good. I'm about to take it for a test spin and check performance.

Next step is to recheck those compression numbers. Last time the average was like 1) 225, 2) 220, 3) 180, 4) 70, 5) 90, but it was my first compression test and it took me a long time...meaning the engine definitely wasn't still piping hot by the time I got to cylinder 5.

I think I'll do the compression test through the glow plug holes this time. 1) I already have the adapter, 2) I want to test to make sure all the glow plugs are working, and 3) I don't want to buy new heat shields. Is there anything I need to know about this way of doing the compression test? Seems like I recall some differences...

Thanks again, everyone!

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1980 300SD Turbo Diesel
"Bailey's. Mmm...creamy. Soft, creamy beige." - Old Gregg

It was definitely harder to start after about 30-40 minutes of sitting. Just to make sure, and since it's so cheap, I replaced the inline fuel filter...and after priming with the hand pump a whole bunch of times it started right up. I still wonder if it's somehow not getting enough fuel delivered from the fuel pump, cause everytime I've cranked the hell out of the manual primer it seems to start with no trouble, even without throttle...

But we'll see how she performs tomorrow morning and after...

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1980 300SD Turbo Diesel
"Bailey's. Mmm...creamy. Soft, creamy beige." - Old Gregg

Well, I couldn't get it to start again this morning. The battery is nice and strong, and even with a jump I couldn't get it to fire up.

Would this be a good time to run the compression numbers again (assuming I can get it started at some point to get a hot engine) and check the glow plugs while I'm at it?

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1980 300SD Turbo Diesel
"Bailey's. Mmm...creamy. Soft, creamy beige." - Old Gregg

See if you are getting white vapor from the exhaust when it won't start. If you do, it has fuel but is not firing due to low compression of GP issues. If you don't, it's not getting fuel. Temporarily remove the overboost protection switch and start it with WD40.

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'83 300D, 126K miles.

Sorry, I should've mentioned that...yes, there's a ton of white smoke that comes out of the exhaust when it finally does start. So that means it's getting fuel, huh? And I've had to give it at least some, occasionally full, throttle to get it to start, so that explains the large amount of smoke.

Well poop. What do you mean by GP issues? I'll attempt to get it started and do the compression test again next week.

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1980 300SD Turbo Diesel
"Bailey's. Mmm...creamy. Soft, creamy beige." - Old Gregg

I should have been more clear on the smoke. Look for the smoke before it starts after you've cranked it for 5-10 seconds. The smoke you see after it starts could be the results of the GP's not working properly or your lower compression cylinders not firing.

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'83 300D, 126K miles.

When parked is the nose of the car level, pointed up or pointed down?

On my 85 300D i had a air leak after replacing the spin-on fuel filter....whenever i parked the car nose up an incline it would not start and needed to be hand primed 6 - 12 times before it would start. Been awhile now but my original thought was the bolt was too loose.... ended up replacing the internal O-rings on the hollow bolt that the spin-on fuel filter attaches to and that did the trick.

I also have a 116 same year as your's and there is only one O-ring on the bolt. I used the smaller O-ring as on the 85.

Look for fuel filter kit about halfway donw the page...
Back to the* Mercedes Diesel parts for sale



Chris

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1985 300D, 250k
1980 300SD, 180K

I have a good friend that says this all the time..."Interesting theories." Unfortunately mine's parked flat as a dark aged priest thought the world was.

Also, recently, I hand pumped the manual primer probably 40-50 things before and during trying to start the car, and it still wasn't turning over.

Haven't done anything on it since last update, so I'll report back sometime after thanksgiving.

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1980 300SD Turbo Diesel
"Bailey's. Mmm...creamy. Soft, creamy beige." - Old Gregg