More grist for the mill:
17 below zero F here this morning. Both cars plugged in . My wife went out to start the 116. It fired on the first compression stroke but my wife let off the starter before it was fully running and it stopped. She tried repeatedly to start it. No go.
This further complicates the 'you only get one chance to start it' issue. Since the engine was relatively warm (I opened the hood to confirm), I would have expected it to start on the second try or third try. Could it be that the fuel in the immediate vicinity of the engine is warm from the heater but the initial start attempt circulates that warm fuel away from the engine and all later attempts are using cold fuel and that is the major factor in the 'one chance'?

The TD started on the first compression stroke. After I confirmed we had one running vehicle I went to the 116 to give it another try. This was about 10 minutes after my wife's failure. No firing at all after a 30 second glow and I had to crank it for about 30 seconds before a single cylinder started firing and another 10 seconds before enough cylinders were firing for it to run on its own. This is with a warm block.

__________________
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

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?

This doesn't bode well for compression. Time to get a compression test and see what you've got. Trying to chase a compression issue is simply a waste of time.

How many miles on the 116?

I understand that it allows the glow to continue after the ignition switch returns to position 2 (following a start from position 3). This is in the FSM and owner's manual which indicates to me that if you are starting the safety shutoff is ignored (or extended) and the glow continues as long as you're cranking to start and then shuts off when the key returns to position 2.

What I don't understand is, reports of the afterglow relay and violet mod giving up to 2-3 minutes of glow.

If the relay timer isn't disabled and you're only allowing the normal cycle length to continue after a start, how is the reported extended glowing possible? ... or was it misinformation?

__________________
Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

I did it last year. (3k ago) About 330 psi cold on all cylinders. It's got around 115k on it.

__________________
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

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

__________________
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

You won't get anywhere near 2-3 minutes with an original equipment relay. All you will get is whatever is remaining of the original glow cycle, which is around 40 seconds, depending on temperature.

The aftermarket Bosch relay will give a 3 minute afterglow, however.

http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1983@@1983&makeid=63@@MERCEDES%2DBENZ@@63&modelid=6232@@300TD&catid=241959@@Body+Electrical&subcatid=241967@@Fusebox+and+Relay&applicationid=W0133-1606169&mode=PA

As designed, the glow cycle is terminated (regardless of time elapsed) when the key is released from the start position. Disconnecting the violet wire prevents the timer from ending the cycle prematurely, since it doesn't "know" that a start was attempted. So the cycle will run for its "normal" duration until it times out. So, the most that you could nominally expect is an additional 30 seconds, plus or minus.

Thanks.

I seems then that the cost of the Bosch afterglow relay would be worth it, compared with doing the "free" violet wire mod, for someone with a rough idle after starting.

__________________
Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

I bought one last winter when my original relay got to the point where the cycle lasted only about ten seconds. (I was more motivated by price than the afterglow feature.) It still takes a minute or so for the engine to smooth out when cold, so I can't say that the difference is earthshaking. But I probably need to check my plugs again; they could be a factor.

I also bought the new afterglow relay last year, mostly because it was cheaper than a new original relay, and I didn't want to get a (second ) bum relay from ebay. I also got 5 new plugs with it, to make sure I had plugs rated for the extended glow time.

The wagon starts pretty easily and idles fairly well on cold mornings after starting, but it wasn't too bad before either, so I don't know how much the afterglow really helps...my car wouldn't make a good test for it. I have a feeling all its doing is shortening the life of my glow plugs

Speaking of which, are the plugs sold from Fastlane rated for "afterglow"?

__________________
1985 300TD-euro 352,000 mi
1974 240D (1?)52,000 mi - has a new home now

That is a pretty good compression number - on the order of 22 atmospheres - especially for a turbo. Typically a turbo has a lower "nominal" compression ratio since under load it gets a pressurized slug of air.

If that is truly your compression, the only issues I can attribute your problem to are the glow plugs are not up to snuff, and your injectors are likely a little leaky. This, in combination with the cold freaking air being sucked in and circulated around is quenching the combustion attempt before it gets going. The first shot has a presumably dry set of glow plugs reaching a relatively high temperature for the first shot of fuel. If that fuel arrives imitating mucus from a sneeze instead of a fine spray, the combustion is not going to be complete. But, if the engine speed is increased while you continue to crank the starter, the engine will fire as it climbs up the thermodynamic capability curve with higher speed. IF you stop before the engine is running, the glow plugs will be wet, and they won't really be hot when the glow cycle is over - they get cooled as the wet fuel evaporates. The combination of cool plugs and cold air being sucked in conspires to make starting difficult or impossible the second time around.

When the glow plugs and injectors are not up to snuff, on a really cold day you are going to wear down your battery and weaken your starter. Which makes things just that much worse.

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)

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

__________________
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?

__________________
'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)

One could just hold the stop lever down, or modify the vacuum system with a separate "off" control.

-Jason

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.