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Discussion Starter #1
Hello,
I purchased my first M-B about a week ago. It is a 1985 300D with 223,000 miles. I drove it home from Cincinnati, which is a 200 mile drive. The car ran flawlessly. :D I have been driving it without incident for several days, but now it will not start. :cry: When cranking the engine there is no diesel smell. I question if there is a malfunction with the fuel shutoff on the injector pump. Any thoughts as to this problem? I miss driving her. :cry:
Thanks,
Nate
 

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Congrats on your buy, Nate!

To check the fuel shutoff, just make sure that the lever is up before you start it (and during starting if you still are not sure). If you are not familiar with it (sounds as though you are), it is the lever on the IP with "stop" written on it (may have faded away).

I understand it is pretty cold there right now. Is the car in a warm garage, or out in the weather? Does the glow system seem to be OK?

Sometimes pre-glowing two or three times before starting can be very helpful in cold weather.
 

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Discussion Starter #3
Thank you for the tip. The car is in the garage. I am familiar with the fuel shut off and it seems to be in 'run' position and glow plugs are working. (The previous owner demonstrated how it worked before I purchased the car) It definitely is not getting fuel because after cranking the engine there is no smell what so ever. Before it quick working I always had a diesel smell in starting the car, as those days were very cold and it took two or three attempts to fire the engine. What I was wondering is there a possibility that some part of the full shut off became disconnected inside the pump? I have been looking for diagnostics information, but so far I am not finding any.
Thanks,
Nate
(missing my Benz) :cry:
 

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If that has happened, it would be the first that I have heard of it. The best bet would be the two fuel filters. There is a clear one going into the IP, and a metal one that looks like an oil filter somewhere near the front (silver in color typically). For any used diesel purchase, it is recommended to replace these for exactly this reason. Also, check the valve adjustments when you get a chance. You might want to check the air filter and put in some diesel fuel system cleaner and replace any hoses that appear to be dry or cracking.

To see if your really are not getting fuel (don't count on smell), you can loosen a line fitting at the injector and watch it while somebody cranks the engine a couple of times.
 

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Discussion Starter #5
Well, here is what I have done:
I had to order the fuel filters and I should have them in by tomorrow night.
I loosened an injector and cranked the engine-no fuel at all.
Next I loosened the line from the filter to the IP at the IP. I operated the primer pump and fuel was plentiful at that location. Very puzzling.
As far as the value adjustment I have to check the actual mileage, but I do know htat it was done not all that long ago. When I looked at the car the owner took me through the log books, page by page. The air filter is rather recent as well. The hoses look OK.
Thanks,
Nate
 

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When you replace the filters, be sure to use the primer pump again.
 

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Discussion Starter #7
I went and picked up the fuel filters, however, I was only able to install the primary filter because the other filter had the incorrect thread size. So I will have to see about getting the correct filter this next week. I also know a diesel mechanic who is going to take a look at it.
Nate
 

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Someone recommended I try spraying starter fluid

Hi, I'm in La Jolla California (Near San Diego)
My 83 300dt wont start either -- well, it won't start today, but it has generally been hard to start in the morning anyway ..
Yesterday, I spent hours trying to jump start it -- no luck and it didn't even siound as though it was getting gas or igniting the gas (diesel) if it was getting it ..

Someone recommended I try spraying starter fluid and so I am gouint to go out and try that right now .... I'm also going to check the glow plug relay switch board to se if my glo plugs are even lighting up ....

Any ideas please?

Reply here or to my personal e-mail box: [email protected]

thank you for any help you might lend.

Rory D Izsak
 

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Sound like you are on the right track if it is not a fuel flow problem by chasing possible glow system gremlins. I would avoid using starting fluid, though. Any luck with this?
 

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Discussion Starter #10
The car is now running!!

I replace 3 of the 5 glow plugs and then tried to start it. Victory!! :D Now just to replace the other two. What has been confusing in all of this is the glow plug light on the dash. It seems to work intermittently and is slowly getting worse. :? What controls the glow plug indicator?
 

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Glad to hear you got it going!

The glow plugs are basically controlled by a relay which uses the resistance of the glow plugs as part of its operation. If the glow plugs are bad, that could cause the function and therefore the dash light indicator indicator problems you are seeing. Of course, it could just be a bad relay too... (as for your next question, I am not sure where it is located on your car)
 

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Rory - Yikes! No ether please

Rory:

  • Our diesels are designed for combustion in the pre chamber, not the cylinder.
    Ether also strips any lubricity you get fom diesel fuel.
    Ether does not have the timing control you get with the injection pump. Detonation before the valves are completely closed can push a valve open (interference engine).
Although use of starting fluids has been done time and again, your rolling dice.

Let's get that problem worked out, no bypassed. Start with a resistance reading across each glow plug, with the glow plug harness unplugged from the relay (just follow the wires from the plugs back to a connector on a black box).

Sincerely,
Scott
 
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