1982 300D won't start -- is engine turning fast enough? - Page 5 - PeachParts Mercedes-Benz Forum

leathermang · #61 09-10-2014, 11:46 AM

So you think air forced through those hole ( praying your first movement of that piston is UP ).... will blow carbon chunks up and 90 degrees out the glow plug hole ?

Do you know what the direction of those holes is ? ( hint Radial ) ... not longitudinal up the precombustion chamber...

and better check your chemistry set again... ' burning carbon '.... ?

and again you put words into my post... I did NOT say the carbon would be sucked into the combustion chamber ... that would be IDEAL compared to what I say it will do... that is clog one or more of those holes... OR mess up the area the fuel is supposed to HIT after being atomized by hitting the PINTLE... messing up proper dispersal into the holes...

thus messing up your spray pattern.... and your power.....and your mileage...making for a rough engine .....due to uneven power from the pistons...

funola · #62 09-10-2014, 02:17 PM

Carbon that's smaller than the drilled holes will get sucked into the combustion chamber and be expelled out the exhaust valves, carbon bigger than the drilled holes will not jam the holes and will be blown out the glow plug holes during the FSM recommended purge crank cycle. Whatever carbon not blow out that is in the pre chamber will get burned within the pre chamber (that's where the fuel starts to ignite). I'd think it's red hot in the pre chambers.

leathermang · #63 09-10-2014, 02:27 PM

At what temperature does carbon ' burn ' ?

LOL...

Only your first sentence is true....
But... do you know how small those holes are ?
what are the chances that pieces broken off in the reaming process will be that small... ?

Can you point me to that FSM reference ?
I have not seen it.... and many times the info for something is hidden in another section.. or in a ' maintenance ' manual published later ...

hawkwing · #64 09-13-2014, 08:49 PM

Quote:

Originally Posted by sloride

Did you get it restarted after running out of fuel, and then ran the battery down with the parking lights being left on or never restarted after running out of fuel? What is the throttle position while trying to crank it (try flooring it until it catches)? It sounds like it is firing on one cylinder or two. With a newly purchased car you should change two fuel filters, confirm that the tank strainer is not plugged, and that you are getting fuel to all injectors with the hard lines cracked at the injectors. Then cycle the GPs twice for twenty seconds then crank. While changing GPs I also spray a shot of WD40 in each prechamber after using the small brush to remove carbon flakes from the reaming process, seems to help restarting with out any trouble. My $.02

Well sloride and funola win the prize -- I had overlooked it before but finally I tried blowing out the tank strainer with a bike pump and it started right up. One clue that I should have paid attention to was that the clear pre-filter was almost full, which I now think was a sign of the clog in the fuel delivery -- once I cleared the strainer the pre-filter emptied to about half full. Thanks for all the tips everyone, I really appreciate it and I'm sure I'll be back! cheers

1982 300D good start - YouTube

Silber Adler · #65 09-13-2014, 09:24 PM

I am always amazed at the simplicity of repairs of these cars.

cooljjay · #66 09-13-2014, 10:02 PM

You might want to pull the tank and clean it plus the strainer or replace....the clog will be back, and the only way to get it out is to remove the tank....

hawkwing · #67 10-27-2014, 06:07 PM

Well, as a bit of an update:

1) I changed out the 15W-40 dino diesel that it came with for 5W-30 Rotella T6 synthetic
2) I adjusted the valves (all tight, of course)
3) I bought a '77 240D for $600 and did the above to it as well (the second valve adjustment took 1/4 the time as the 1st)

... and now I have 2 functioning MB diesels! They both start right up without being plugged in down to at least 15F, and we're just dropping below that so we'll see how low we can go (it usually gets down to -40F at some point).

video: http://youtu.be/8MKlJ9-c7NU

The red '82 300D has a block heater, battery heater, and oil pan heater, but I think I need to add a trickle charger because most of my trips are pretty short and the battery gets worn.

The blue '77 has a block heater, oil pan heater, and coolant heater. It clunks pretty hard on startup but seems to be more reliable at low temp than Red.

Now just a couple more issues to fix, like the flaky heater and dead speedometer on Red, and the broken door on Blue...

cheers-