Hey folks,

I posted this question over in Vintage and think it might get a little more love over here.

As of two days ago I had a '76 300d daily driver. Rough starting in the morning, but if I plugged it in there weren't too many problems.

Next thing I know I attempt to start it in the morning (plugged in) and all I got was the motor turning over.

I unplugged a bunch of hoses and lines to find out that I am getting fuel to the Injection pump but not out of the pump (either when cranking the engine or using the primer pump).

I spoke with a diesel mechanic who doesn't specialize in Mercedes, but thought it was the IP. Anyways, I am looking for a direction to confirm/deny the IP problem.

Thanks,

Dave

Is this a Fuel Injection Pump with a Pneumatic Governor?

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84 300D, 82 Volvo 244Gl Diesel

Honestly I don't know 100%. Looking at the Service manual it appears to be mechanical. It is a 617 engine and the manual only talks (as much as I have read) about it being a Mechanical Governor. I haven't gone out to the car to be certain.

What exactly am I looking for?

Dave

If your fuel filter had trapped some water and it froze overnight you wouldn't be getting any fuel. How old is the fuel filter?

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

I think your IP has it's own oil reservoir, be sure it's full.
+1 on the water in the filter.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

We aren't freezing overnight, plus I tried to start it later in the day with change. I am guessing that filter is around 1.5k miles.

There is no fuel out of the hard injector lines?

When you use the hand pump, does fuel come out of the return line from the IP?

The OM617 never had a pneumatic governor.

That is correct, there is no fuel out of the hard lines.

As far as the return line goes, I will check Wednesday when I get home from work.

Thanks for the reply.

Dave

You cannot get fuel out of the hard injector lines by using the hand pump. During cranking there should be fuel coming out if you open the lines.

When you use the hand pump, do you hear a buzzing noise of the pressure release valve opening? Do you see fuel moving in the return line from the pump?

I will check Wednesday. No fuel out of hard lines when cranking over.

That is usually caused by the lack of fuel to the IP.

I have fuel going into th IP

Either there is not enough fuel pressure in the gallery, because of air in the system or the pressure relief valve on the back of the pump isn't working properly.

The other possibility is that the rack is stuck. You can try flushing the pump with gas helps (don't run the pump with gas!).

Thanks, I will give it a shot