Hey everyone,

As you may or may not know I am a new owner of a '78 240D 4spd. It has 128K miles on it. The PO had recently changed the glow plugs before I purchased it and done a fuel system cleaning(still the original style AFAIK, and not sure how severe the cleaning was), but it has some difficulty starting when cold. I haven't licensed it yet so it's been sitting. The glowplug light does come on for a full cycle, but it still starts hard.

I am new to diesels (especially 30yr old ones) and am not sure what to expect.

Thanks to all!

Try leaving the glowplug on a timed 45 seconds.... forget the suggestion light... and report back...

You have a series glowplug system on that engine if it is still OE. You can tell if it is working by looking at the heavy squiggly wires that join the plugs. Particularly at night, these will glow red. If they don't, your glowplugs are not working. On that system, if one glowplug goes out, none of them work.

If your glowplugs are not working I would recommend a change to the retrofit pencil plugs

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Are the valves adjusted properly?

Scott

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Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

Thank you guys for the quick replies,as usual. This forum has been THE BEST forum for answers PERIOD!!

Valves haven't been checked yet but are on the TO-DO list.

How do I keep it on a 45sec timer? Cycle it twice or is there another way?

I will to the 'night time' glow-in-the-dark check ASAP as well.

One other thing, is there as quick way to tighten the alt. belt? (The adjustment bolt has seen better days.)

Thanks again!

I forgot to mention, this is starting it from an unheated underground garage.

Thanks!

Where? Fairbanks or Miami?

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Do not recycle it... that light is not really connected to the system... in that when it goes off it does not turn off the glow plugs..
So you just turn on the key, ignore the light, time it... then turn the key to ' start'...

Leathermang, is the glow plug light time controlled by the glow plug relay?

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Kevin

1978 300D
1979 240D

I could have been more clear I guess! Toronto, Canada!

So 45 seconds is the standard cycle time for the loop plugs?

I have them on a manual pushbutton switch (PO modification) and have been experimenting with different cycle times. It seems to start best with 90 seconds when it's well below freezing, down to about 30 seconds in the summer. Does this sound right?

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

The relay does control the time of the light to a very limited extent. You might get another 7 seconds in the bitter cold. But, the relay remains engaged for approx. 35 seconds, independent of temperature and independent of the light.

So, use whatever time you need.........up to the full 35 seconds........to get a smooth start.

What I am going by is the Factory Shop manual saying that the glow plugs continue to heat up for about a minute ... they even give the temperatures they expect them to get to... and being conservative...as usual... I suggested he keep it engaged for 45 seconds...

While I've never actually timed a 616, the statement "about a minute" translates to 35 seconds on the SD and the SDL.

The loop plug light in my 77 300d stays on for an eternity compared to my 85 pencil plug relay. Then again the light stays on much longer in my 79SD than the 85 even though it has pencil plugs. I've never actually compared the actual times the plugs are energized.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13