300D Won't Start - PeachParts Mercedes-Benz Forum

robbittt · #1 02-22-2011, 09:29 PM

Help, please anyone! I'm so frustrated with my beloved car...
I have an 85 300D. I was running SVO for a while; she started running a bit rough and was hard to start. Eventually I had to press on the accelerator to get her to start. I put in dinofuel but she ran even worse, stalling every time I took my foot off the accelerator. I bought diesel purge, but she quit as I pulled into my driveway from the auto parts store. I haven't been able to get her started ever since. The engine was rebuilt 2 years ago. I found evidence of algae buildup, so I've since:

took down fuel tank and cleaned it out
cleaned fuel lines
replaced both filters
replaced injectors and heat shields
replaced all rubber return lines
replaced glow plug relay fuse
replaced glow plugs
used a reamer kit and brush to clean carbon in pre-glow chambers

I ensured fuel delivery by loosening hard fuel line to injectors and fuel was being delivered. The injection pump has to be working for the fuel to get pushed, or so I'm told. The fuel lines were bled after priming. Since the motor was rebuilt 2 years ago, I seriously doubt it's a compression issue. I'm just at a complete loss, could anyone please help? It would be sooo greatly appreciated, Thanks!!!!!!!

Biodiesel300TD · #2 02-22-2011, 09:43 PM

You could have gummed up the piston rings enough to cause really low compression. Try putting an ounce of brake fluid or Marvel Mystery Oil(MMO) in each cylinder. Let it sit as long as you can let it, give it at least a day. You'll have to remove the injectors before you do all this or course. After it has sat for a while turn the engine over while having someone hold rags over the injector holes. This will blow out any excess brake fluid or MMO. Then put it all back together and try to start it.

leathermang · #3 02-22-2011, 09:45 PM

Have you set the valves lately ?

Do you have a Factory Shop Manual ?

robbittt · #4 02-22-2011, 09:48 PM

Quote:

Originally Posted by Biodiesel300TD

You could have gummed up the piston rings enough to cause really low compression. Try putting an ounce of brake fluid or Marvel Mystery Oil(MMO) in each cylinder. Let it sit as long as you can let it, give it at least a day. You'll have to remove the injectors before you do all this or course. After it has sat for a while turn the engine over while having someone hold rags over the injector holes. This will blow out any excess brake fluid or MMO. Then put it all back together and try to start it.

So pour the oil through the injector holes? Should I crank the engine a couple of revs to lube it up a bit? Thanks!!

robbittt · #5 02-22-2011, 09:50 PM

Quote:

Originally Posted by leathermang

Have you set the valves lately ?

Do you have a Factory Shop Manual ?

Wouldn't the valves have been adjusted during the rebuild? I do have a Haynes manual...

leathermang · #6 02-22-2011, 09:51 PM

The valves are to be set about every 20,000 miles...
Have you read the Haynes manual ?

Sent PM....

robbittt · #7 02-22-2011, 09:56 PM

Quote:

Originally Posted by leathermang

The valves are to be set about every 20,000 miles...
Have you read the Haynes manual ?

Sent PM....

Yes, but missed the 20,000 mile valve adjustment. I did most of the troubleshooting. I've never done an adjustment, is it relatively simple? Thanks!!!

kerry · #8 02-22-2011, 09:57 PM

I hate to be the bearer of bad news but those symptoms are often reported when an IP fails from having been run on SVO. How long did you run it on SVO?

leathermang · #9 02-22-2011, 10:04 PM

Quote:

Originally Posted by robbittt

Yes, but missed the 20,000 mile valve adjustment. I did most of the troubleshooting. I've never done an adjustment, is it relatively simple? Thanks!!!

Relatively simple... yes.... but important that you follow the rules exactly..
and those rules are spelled out in the Haynes manual....
What are you using the Haynes manual for ? To raise your height in your chair ?
Go read the Haynes manual and come back and ask questions based on what you do not understand from its presentation. It has better pics than the Mercedes factory shop manual.

robbittt · #10 02-22-2011, 10:05 PM

Quote:

Originally Posted by kerry

I hate to be the bearer of bad news but those symptoms are often reported when an IP fails from having been run on SVO. How long did you run it on SVO?

About a year, but if that were the case, wouldn't I be getting no fuel to the injectors?

leathermang · #11 02-22-2011, 10:10 PM

SET YOUR VALVES.... then come back if that does not help...

barry123400 · #12 02-24-2011, 06:38 PM

Quote:

Originally Posted by robbittt

So pour the oil through the injector holes? Should I crank the engine a couple of revs to lube it up a bit? Thanks!!

No just let it soak. Leave the block heater plugged in as well to aid the chemical action if you have one.

Or just do a compression check to verify that the rings do need cleaned up. Having fuel at the loose injector lines is possible with damaged injection pump elements as there is no indication they are capable of raising the fuel pressure to the opening point of the injectors and beyond.

There also have been a few cases reported of injectors gummed up or having some problem as well on on vegatable oil. If for example I purchased your car and I have purchased a prior vegatable oil car. There are a whole lot of cleaning things I would do including a real internal soak of the injection pump with a good solvent before using the car.

The worse thing to fear is the wvo has caused the rings to tear up the cylinder bores. If something like this has occured it would be a real shame as the engine was rebuilt a couple of years ago. Running a single tank system with no heating and poor vegatable oil probably contributes to this severe problem. Also if the wvo was not properly dewatered it is like putting sandpaper through the injection pump.

psaboic · #13 02-24-2011, 07:40 PM

No one has stated the obvious yet, so I will. Change both the fuel filters first. It is easy and solves many no-start issues, especially if the car was running before the no-start issue. Just be sure to pre-fill the spin on filter first, then crack each injector line and crank until fuel dribbles out (to purge out any air. Then tighten up the injector lines and it should start and run. If not, post back and we can go from there

I know you stated in the original post that you changed the filters, but if you still have crud in the tank, they will clog again in short order.

Diesel911 · #14 02-24-2011, 09:58 PM

Quote:

Originally Posted by robbittt

So pour the oil through the injector holes? Should I crank the engine a couple of revs to lube it up a bit? Thanks!!

If he did that he would need to pay for new Injector Heat Shields.

When I did my Marvel Mystrey Soake I used fome skinny plastic tubing shoved in a Funnel with Tape wraped around the end so I could instill the Oil through the Glow Plug Holes.
That way you save a little money by not buying Heat Shields.
I also reamed out the Carbon from the Glow Plug Holes as an added bonus.

Diesel911 · #15 02-24-2011, 10:05 PM

Quote:

Originally Posted by psaboic

No one has stated the obvious yet, so I will. Change both the fuel filters first. It is easy and solves many no-start issues, especially if the car was running before the no-start issue. Just be sure to pre-fill the spin on filter first, then crack each injector line and crank until fuel dribbles out (to purge out any air. Then tighten up the injector lines and it should start and run. If not, post back and we can go from there

I know you stated in the original post that you changed the filters, but if you still have crud in the tank, they will clog again in short order.

I agree that if your Tank is contaminated Filters Can plug up fast. When trouble shooting it is easier just to change them and elimnate them as a source of the problem.
Fuel Tank Screen plugged? Swap the positions of the Fuel Inet and Fuel Oulet Hoses; but have at lease a 1/2 Tank of Fuel.

Even though you are seeing Fuel coming out you might not be getting enough Fuel volume.
It could be that your Fuel Supply/Lift Pump is gummed up inside and keeping the Valves from sealing or your Pressure Relief/Over Flow valve (see cervans very long thread) is having an issue and not allowing the Fuel supply pressure to be high enough.

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