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1993 190E, 1978 300CD
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Discussion Starter #1
OK, all you dieselites!

I dragged home a 1978 300CD this weekend that had been sitting for over a year. It doesn't start. Battery first. Slow chug, but fuel squirting from braided injector lines. Order new ones. Check. The glow light doesn't go out. How long should I wait? On my 85 300SD, when a plug was bad, it would not come on at all, and when replaced, took only about 4-5 seconds. I'm thinking plugs, and maybe one of those conversion kits to the pencil type for faster starts.

What next? Where should I start? Change oil? Its black and cruddy, and I have no idea how long its been in there. Change fuel? Its bound to be yucky, and may be one reason it won't start. The guy I bought it from said it might need injectors. How can I tell? All help greatly appreciated.

Ken
 

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1981 W123 300D non turbo, 1992 190E 1.8 <=> 2.0
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6,561 Posts
I think even a cold oil change will probably help get the crank spinning a bit quicker - if it has been sitting for years it could have lots of nasties in it. My choice would be to put in a new oil and filter but change both again pretty quickly after getting the car running.

I'd remove all of the old fuel and dispose of it responisbly.

Replace the fuel filters too.

Get a strong battery.

Check the air filter isn't clogged and go for it!

There's lots of other stuff you could do but I'd save most of that for when you've got the thing running.


When replacing the fuel you should bleed to the injectors.
 

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1985 300D Gone 1985 230CE Perfect, 1984 300TD Driver, 1981 300TD Bad engine
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1,418 Posts
I don't think that I have ever seen these diesel engines with braided injector lines. If fuel squirts out anywhere that is bad. Perhaps someone thought it would be cool to replace the solid tubes with braided hoses. They may not be able to handle the pressure and are compliant enough to absorb the fuel shot. They need to be replaced.
 

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1984 300D
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5,070 Posts
I think the Braded Injector Lines He is speaking of are the Fuel Return lines. He has not learned "Mercedes Diesel Speak" yet.

When replacing the fuel you should bleed to the injectors. = Loosen the Fuel Injection Line Tubing Nuts at the Injectors. That will bleed the Air out of the Fuel Injection Lines. If Air gets trapped in there it compresses a lot and mover only a little bit and can result in Dear Batteries and stressed Starters.
You will need to know how to do the above if you ever run out of Fuel.
It is also valuable in that it tells you if you are getting Fuel up to the Injectors.

Pumping on the Hand Primer brings Fuel up to the Fuel Injection pump Housing and back out of the Fuel Pressure Relief/Overflow Valve. That is Fuel Supply System and is the low pressure part of the Fuel System.
The Hand Primer will clear the Air out of the Fuel Injection Pump Housing. But, will not remove the Air From between the Fuel Injection Pump and the Injectors in the Fuel Injection Lines; the High Pressure part of the System.
 

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1984 300D
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5,070 Posts
OK, all you dieselites!

I dragged home a 1978 300CD this weekend that had been sitting for over a year. It doesn't start. Battery first. Slow chug, but fuel squirting from braided injector lines. Order new ones. Check. The glow light doesn't go out. How long should I wait? On my 85 300SD, when a plug was bad, it would not come on at all, and when replaced, took only about 4-5 seconds. I'm thinking plugs, and maybe one of those conversion kits to the pencil type for faster starts.

What next? Where should I start? Change oil? Its black and cruddy, and I have no idea how long its been in there. Change fuel? Its bound to be yucky, and may be one reason it won't start. The guy I bought it from said it might need injectors. How can I tell? All help greatly appreciated.

Ken
The Loop/Filiment type Glow Plugs are a different Ball Game. If one goes bad they all stop working.
You can update them to different adapter type Glow Plugs but it is one of those issues where right now you just want to see if the Engine is going to run.
I will PM some info to help troubleshoot the Glow Plug System.
Also do not test the individual Glow Plugs acrossed the Battery as it will instantly burn them out.
The zig-zag metal Glow Plug Wires should not be touching the Engine Block or Cylinder Head except where they Bolt to the Glow Plugs.
 

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1993 190E, 1978 300CD
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21 Posts
Discussion Starter #6
Its ALIVE!!!

Whoot! the Benz started and ran on its own this afternoon!:D

Thanks for the advice everybody. I changed the oil and filter, just took the air cleaner off for now, since O'Reiley's didn't have one. Put in Kent B's pencil glow plug update kit, and replaced the braided lines that go to the injectors (return lines?).

After I got a whiff of the fuel filters, I knew I had another problem. I should probably put diesel in instead of gas!:eek: Yes, some PO had put gas in the car, so I will be draining the tank. For today, I just used fresh fuel in a gatorade bottle.:thumbsup: After significant chugging and clearing both gas and probably some air, she ran! Like a sewing machine! Now if I can only chase down that pesky vacuum line so I dont have to push the stop button to shut it off!:rolleyes:
 

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2001 Volvo V40
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2,954 Posts
The glow light doesn't go out. How long should I wait? On my 85 300SD, when a plug was bad, it would not come on at all, and when replaced, took only about 4-5 seconds. I'm thinking plugs, and maybe one of those conversion kits to the pencil type for faster starts.
You've updated your glow plugs, but normally it would take about 30 seconds for the light to go out for these old glowers.
 

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1993 190E, 1978 300CD
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Discussion Starter #8
Yeah, the glow cycle is much better now. Although, I'm sure the inability to start was mostly fuel related. See above.
 

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1993 190E, 1978 300CD
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Discussion Starter #9
I appreciate all the help. I got her running under her own power today. New glow plugs, filters, and a set of used but checked injectors. Got some questions, though. A couple of the injectors and heat shields were very oily when I pulled them out. I assume that's not good. Cleaned everything, new shields, and no more leaks!

Got it running and ran a can of diesel purge through and boy did it smoke! I took the oil filler cap off and lots of smoke coming out. A pretty loud valve train clatter on second hole from the front, #2? Could that be valve adjustment? Just bad compression? Haven't done a complete test yet.

Also, the engine won't shut off, even with the STOP switch. It slows some, but doesn't quit. I had to pull the fuel line. (I broke the vacuum tab to the brake booster line :-(). Any other quick ways to shut it off?

I appreciate all the help!
 

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1984 300D
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Connect a section of Vaccum Hose to the Vacuum Shutoff on the Fuel Injection Pum and use a Hand Held Vacuum Tester type Pump a.k.a Mighty Vac and create vacuum with it or simpy suck on the Vacuum Line.
If it shuts off but you find Engine Oil in the Vacuum Line your Shutoff is leaking some and at some point is going to need to be replaced.

The Manual Shutoff should shutoff the Fuel Injection Pump.
If you have an MW type Fuel Injection Pump the shutoff pushes on the Throttle Lever that pushase against a Spring Loaded Plunger that is inside of the Idle Adjustment Screw. The Plunger has been know to rust up inside of the and not move like it is supposed to.

The other thing is if the Idle Screw has been adjusted down too for or there is some issue with the Linkages adjusted wrong.
Also on mine it is possible for the Injector Return Hose to interfere with the Manual Shutoff Lever if the Hose is not routed properly.

Prior owners almost never adjust the Valves. Some of it is that they just don't know they need to be adjusted because for quite awhile most Cars have had Hydraulic Lifters on them so people think the Mercedes does.
The other part is the cost to Pay a Mechanic to do the periodic Valve Adjustment is more than most People want to pay so as long is it starts and is drivable that is what people do.
When the Car Runs Bad the never think it is possible that a Valve Adjustment could be the Cause; and get rid of the Car.
 

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1993 190E, 1978 300CD
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Discussion Starter #11
How much vacuum should I generate on the shutoff valve? I have ordered a new brake booster hose, because that is where it is broken. :crybaby2:
 
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