It recently got so cold here in South Florida (47F) we had to actually wear socks and my 1984 300D is having an issue.


Being a transplanted Northerner (Michigan) I had tried to winterize my fuel with some additives. But here is the issue.


The MB will will start and run for 7-10 seconds then die. If I pump fuel with the manual pump (about 5-7 pushes) - same thing- the MB will fire right up - run for 7-10 seconds and die.

Replaced the small clear fuel filter and larger fuel filter- same thing the MB will will start and run for 7-10 seconds then die


Even did the old fill the large Fuel filter with ATF and pump manual pump - but no difference -same thing - The MB will will start and run for 7-10 seconds then die


Any thoughts ? Or do I need to wait for end of winter next week ?

Was there anything inside of the plastic filter?

Did you change the O-rings on the fuel filter bolt?

Try disconnecting the vacuum shutoff tube from the vacuum shutoff on the fuel injection pump.

Aire leaks? If you have the old hand primer with the shiny aluminum body, they are a notorious source of air and air leak.

Maybe the piston in the fuel supply/lift pump is stuck (it is metal to meat no seal rings) or return spring broke (no one I have read of on this forum has had the spring break issue but when I worked in a fuel injection shop at most 2 times a year a Bosch fuel injecting pump came in with a broken sprint.)

There is a little 5mm O-ring that gets hard or sometimes deteriorates and is totally gone.

The fuel supply/lift pump valve springs can corrode through or can get gunched up with deposits.

There could be an issue with the fuel pressure relief/overflow valve. The length of the spring can become tool compressed. If you have the type that can be taken apart, you can stretch the spring till it has a 27mm free length or buy another one if they still sell them.

I don't know if a clogged fuel tank vent would shut you down that fast. But try stating with the fuel fill cap off and see if it keeps running like that.

If your crankcase pressure is high, it can push the vacuum shutoff in to the shutoff position. It can be a little messy but see if it will keep running without the Oil Fil Cap on. If it runs like that you likely need to clean out your crankcase breathing tubing.

That is some of the possible.

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84 300D, 82 Volvo 244Gl Diesel

Doubt the fuel is gelled at only 47 degrees, so it sounds like it might be a tank vent or fuel tank screen issue. Another diagnostic trick if pulling the cap off the fuel filler does not work is to fill a 5 gallon can with diesel, connect one end of a clear hose to the plastic inlet fuel filter on the pump and put the other end inside the fuel can. Pump the primer to draw fuel from the can and start it up. If it runs longer than 7-10 seconds you have a fuel delivery problem from the tank. If not, then there is another issue.

Good luck and keep us posted.

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2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)

Subscribed to learn .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Fuel just starting to gel???

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

I’m going to commit to carbon build up around the glow plugs , if you buy a glow plug reamer with 5 new monarch glow plugs you’ll be starting the car in the teens . We had that Arctic blast 2 years ago this February. I finished this service shortly before and it made a big difference , made the start up after 2 cycles like nothing , driving in a foot of snow and slush for 3 days . That was a rare site for Houston .

Rereading the 47 degree part , yes , you can check all your glow plugs and do this service to start off , if I’m having any starting issues and have found that fuel is present in the lines and both fuel filters are in check (recently replaced ) , it’s usually the glow works . how many miles on the car should be asked ,if it’s 350 k plus then you need to consider a look at where you are with the motor, my advice , check compression , it’s not the end of the line if it’s short on a few holes , next , valve adjustment , then recheck compression . This is kind of your baseline . You now have a better understanding of how much life the motor has going for it . These motors don’t get high revs plus utilize the best offerings To reach high mileage , some off the charts . But it takes maintenance.

I have a fleet again, 7 deep ,4 300ds and 3 of the coupes , all being turbo models . I was scrambling this time last week before the cold snap , trying to remember which cars I’m driving with correct service on the glow plugs , Some are definitely needing glow plugs , the daily driver I was unaware of a weak system it had til this cold snap of 14 degrees . So , your car may have a block heater , you’ll have a plug somewhere near the a/c dryer . Plug that in for an hour on a cold morning , eliminates the need partially if the glow plug system is failing to deliver full send on all cylinders for a start .This will get you out and about but don’t let the car sit for 2 hours then expect it to start at those temperatures., 😫

Starts, runs briefly and dies pretty much has to be a fuel problem, not glow plugs. Is there any cloudiness to the fuel? If the wax starts to come out of solution it can plug filters before the fuel gels.

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'75 John Deere 450C (times 2)
'83 240D plus parts car
'87 F350, 6.9L IDI
'89 F350 crewcab, 7.3L IDI
'89 F-Superduty, 7.3L IDI
'91 F-250, 7.3L IDI
'91 F-350, 7.3L IDI
'94 F-350 Crewcab, 7.3L IDI
'94 E-350 Ambulance, 7.3L IDI

Run it of a bottle of diesel.
Put a L of diesel or Purge in a bottle put in the supple and return lines and see if it runs. Don't forget to plug the tank lines.

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92 e300d2.5t
01 e320
05 cdi
85 chev c10

you need to keep a log book on what is done on each car.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.