W115 1971 220D Won’t Start after Sitting 20 Years - PeachParts Mercedes-Benz Forum

RLGDiesel · #1 07-23-2022, 02:31 AM

Hello everyone! Just rescued a 1971 220D from an abandoned warehouse where it sat since 2004. No major rust and a ton of potential. Only problem is I can’t get it to start. Before even attempting to crank the motor, I changed the oil, removed glow plugs and turned engine by hand with Marvel mystery oil in the cylinders, replaced the primary/secondary fuel filters and tank screen, changed most black rubber fuel lines, updated original leaking primer pump with new Bosch design, changed injector pump oil, flushed coolant, cleaned oil bath air filter, etc. I notably did not adjust the valves or replace clear plastic lines. I did not remove injectors or IP.

I have cranked the car about 15 times (45 secs with at least 2 min rest between attempts). It occasionally sputters and even started and immediately died one time. Mostly it just cranks. I have cracked the injector lines during some of these attempts and only get fuel from cylinders 1, 2, and 4. No fuel dribble ever from cylinder 3 despite multiple tries with line open. Glow plugs appear to be functioning based on salt shaker light and hot resistance wires.

No obvious air leaks. I’ve hand primed it at least 100 times but don’t get a very noticeable return line buzz.

What’s the next step here? Rebuild injectors, stuck IP rack, glow plugs? I’m at a loss for now but feel like we’re very close.

Thanks!

Luke

t walgamuth · #2 07-23-2022, 08:00 AM

Sounds like a plugged fuel filter or filters. Treat the fuel with biocide and change your filters and report back.

shadetreemechan · #3 07-23-2022, 08:56 AM

I think you are close. Since filters are new, I would guess the rack is stuck from sitting.
I would take a gasoline soaked rag and hold it next to the intake while someone tries to start it. The fumes should wake it up and often once it starts whatever is stuck in the ip will loosen up.
Have you verified that there is oil in the IP? This model has separate oil fill port on top that must be checked and changed.

shadetreemechan · #4 07-23-2022, 08:57 AM

You could also take the cover off the pneumatic governor on the rear of the IP and manually move the rack.

RLGDiesel · #5 07-23-2022, 09:36 AM

Thanks for the ideas. Could the new filters plug that quickly? I still see yellow fresh diesel moving through the prefilter when I manually prime it. I will try the gas soaked rag. Any chance of accidentally messing up IP calibration timing by manually moving the rack?

RLGDiesel · #6 07-23-2022, 09:37 AM

Also IP has fresh oil!

barry12345 · #7 07-23-2022, 10:00 AM

Sounds like injection pump element number three may by stuck at the top of the stroke. From sitting. i would get number three element pumping and if a standard transmission a careful pull start attempt.

You should mention your geographical location. That would be a long time sitting in many of them. May or may not change the approach to dealing with this.

My thoughts are you have to deal with the number three element problem sooner or later anyways. Usually we use wd 40 to see if a block is capable of running.

Chances of stuck rings after all those years depending on location are high I suspect.

RLGDiesel · #8 07-23-2022, 10:32 AM

I wish I could perform a pull start, but the clutch is seized from bad master/slave cylinders. The car was stored in a warehouse in Fayetteville, NC. The engine turned over well with the MMO in the cylinders.

t walgamuth · #9 07-23-2022, 01:50 PM

If the fuel is really contaminated it could plug the filters again very quickly. The tank strainer also could be plugging.

dieselbenz1 · #10 07-23-2022, 04:56 PM

Start it using a seperate fuel bottle filled with a strong injector cleaner or its somerimes called a purge. That should get your pump and injectors working.

RLGDiesel · #11 07-23-2022, 05:00 PM

Ok I changed the prefilter that has some black crud in it. I also tried about 4-5 attempts on diesel purge isolated fuel tank. Cranked with some sputtering until eventually battery/jump box gave up.

porschesam · #12 07-25-2022, 12:33 PM

My 72 220D sat for over 20 years. The injection pump elements were stuck. I removed the fuel lines off the top of the pump and manually tapped them with a small punch to break them loose. Just be careful not to damage anything.

RLGDiesel · #13 07-25-2022, 08:22 PM

Thank you for the tip about freeing up the IP elements. I think this is an air problem.

When I pump the hand primer, I start the hear hissing and bubbling after about 15 pumps. It is not the typical buzzing of fuel coming back through the return system. I replaced the secondary fuel filter o-ring and tightened the cap to no avail.

Additionally, the hand primer loses some resistance after about 20 pumps and I see bubbles going from the lift pump to the secondary fuel filter.

The tank strainer was just replaced. I don't see any leaks under the car.

Thanks again for all the tips.

Idle · #14 07-25-2022, 09:00 PM

I had something like this and it drove me nuts trying to fix everything. I finally ran a length of steel cable through the fuel line from the tank to the engine. Then I tied a metal brush from a gun cleaning kit to the cable and pulled it through like I was cleaning the barrel of a shotgun.

Lots of gunk came out. I also changed the rubber lines from the tank to the steel fuel line as it was cracked and sucking in air. Not much but enough to mess things up.

That made a difference. I can't say if this is your problem but it would not be a bad thing to do.

resago2000 · #15 07-28-2022, 10:17 AM

when cranking, keep the throttle to the floor until it catches.
can also spray some Pam spray cooking oil in the intake.