The consensus of opinion if frequently in error because one person gets it wrong and the crowd repeats "what he said." So instead of acting as a cheerleader for the uninformed masses, why not get out your multimeter (or look at a FSM) and determine for yourself what really happens?

Yes, you're right.

For the record, here's an earlier thread on this issue which also references an earlier comment by Lance who has a push button glow relay and mentions the electrical draw issues of glowing and starting at the same time.

Glow plug timing on 123's

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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

Even the old W114/115 220D and 240D with the knob you pulled out of the dash kept the glow plugs energized during the starter operation - on those cars the "salt shaker" on the dash was de-energized during starting but the rest of the glow plugs stayed "on" until you let go of the knob.

If the glow plugs were shut off, and the car didn't start on the first compression stroke, it wouldn't start from cold iron at all. Cold air, cold steel, cold Diesel fuel = snuffed out glow plugs if they are shut off. The fuel sprays right at them.

Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I see many references to the cold fuel hitting the glowplugs and cooling them off quickly. I remember someone in a thread suggested keeping the fuel off for the first ~5 seconds of cranking, then shoot it in when engine is turning. Has this actually been attempted, and if so, helped anyone?

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'79 240D 4 speed manual 105k miles

That would be a bit of magic if someone did it. The injection system is tied to the crank via the chain that also drives the valves. No easy way to keep everything timed and yet be able to turn the pump on and off while the engine is spinning. But, if you could do it, in some cases, it might help. A nice fine mist from the injectors is probably easier to achieve by having them cleaned or assembled with new nozzles and pintels. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I made that suggestion about a year ago after unintentionally getting myself in a situation of 35 below zero and no block heater. I have not experimented with it yet but I think it would be worth a shot if you're in a desperate situation. Hook the Mity Vac up to the shut off valve, pull a vacuum cutting off fuel, have someone else glow it and then engage the starter for a number of seconds and then release the vacuum on Mity Vac. It couldn't make the conditions worse and those first few revolutions of compression with no fuel but glowing plugs might be enough to get you going.

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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

It'd be easier and more possibly practical if you were to put a solenoid valve inline of the shutoff diaphragm, so that you can push a button while cranking, then release to pump fuel.

__________________
RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

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FACEBOOK: PANZER450

I'm out of my element here so those more knowledgeable will have to comment on this: A quick look at the schematic in Haynes (and it appears to be an U.K. schematic at that) shows that shorting the two outer contacts on the terminal block next to the battery will energize the starter solenoid cranking the engine and also supply power to the glow plug relay. If the key is in the 'off' position wouldn't that prevent fuel from flowing? Then have someone turn the key to the 'run' position and you remove the short?

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1985 300D Turbo
"Evolution is God's way of giving upgrades" Francis Collins

Definitely energizes the starter. I did not know that it also provided power to the glow plug relay. If it does, that is an excellent solution.

__________________
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

Well as it turns out, I did have problems. I started with my foot fully on the pedal and when it started, I got spooked by the high revs, let the pedal go and it promptly died and refused to start again. I then put a bulb next to the battery and ran a trickle charger. It started up then.

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1987 300TD
1984 300D
755,000 KM and going strong
BC Canada

I got bad glow plugs in my 300SD but was able to start in cold anyway...until today, minus 5F in Chicago and windy!!

15W40 oil in my engine not changed yet to 5-40 so not so optimal for the cold start. There was Howe's in my tank for couple hundred miles which makes huge difference, now I fill the tank with bottle of RED LINE RL-3 winterized.
Too far to pull extension cord to my car for hair dryer so I heat the air intake using plumbers butane torch for some time - starts like it's summer.
I am not rushing so much to change my plugs anymore...