Nope. The glowplugs heat the air already in the prechambers as well as provide an hot bulb to aid atomization/combustion of the cold fuel. A heater grid in the GP place will take a few seconds of cranking before it would fire.

There's a video on YouTube of a guy firing up his cummins 5.9 pickup at like 10F with the intake heater unplugged on purpose. It turned over like 1.5-2 times, small puff of smoke out the exhaust, and it was running strong and smooth. Amazing. I did my oil change last night and let the car sit a few hours in the 18F cold before starting it up (let the oil drip out for a while), when I started it I skipped glowing and simply cranked. It rotated about 10 times with not much happening then all the sudden on the 11th crank it went "vrrm!" and fired up....blast of smoke out the rear and it was running smooth. The engine wasn't "cold" per say, but after 3 hours at 18F, it certainly wasn't "warm" either.

Our 300D can start without glowplugs within maybe 15 rotations at around 25F.....it has excellent compression. We've never tried it on my dad's SD....but its almost as good. Not sure if mine could pull that off. Maybe at 40F or a little higher. Never tried.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

heres a nice variety of intake heaters, the cummins one is on the second page...

http://www.phillipsandtemro.com/Files/airintake_ds2004.pdf

pretty sweet and compact

__________________
Cheers,
Robert

I bet a good/properly set up intake heater on our cars would "work" but you'd probably end up cranking more than just using glowplugs. They get the heat right where its needed, the heated intake air has to make its way into the engine while cranking. A lot slower, especially on engines like ours.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I don't think that you'll gain that much. Like others have said the Cummins can start without any aid down to fairly low temperatures. This is largely due to the fact that it is direct injected. So the intake heater works fine in that application.
If the engine starts, what more do you want? I guess I don't understand what the problem with the GP system is? Mine only smokes a little until about 30 sec after startup on a really cold morning. Compare that to my Scout which will smoke horrendous amounts until warmed up.
Probably the single best thing to do to improve cold starting ability (assuming everything else is functional) would be to coat the internals (piston crown, prechamber, valves) with a ceramic heat barrier to reduce heat loss.

__________________
For Sale: 1982 MB 300TD
1995 Chevrolet Suburban 6.5TD

Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel

By DI, I assume you mean direct injection. Which CTDs are direct injected?

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

umm- all of 'em- at least all the b series which are in dodge's are DI.

__________________
1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

Well that's strange, as IDI engines have an injection pump, like the one in my truck.

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

DI vs IDI has less to due with how the fuel is injected, but rather WHERE it is injected. Directly into the combustion chamber or prechamber.

__________________
For Sale: 1982 MB 300TD
1995 Chevrolet Suburban 6.5TD

Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel

I'm confused then. I thought the CDIs and TDIs were directed injected because they had a common rail. So diesels with an injection pump can also be direct injected as long as the don't have a pre-chamber?

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I did the same thing on my Volvo with a starter relay and it has worked fine since 1996. During that time until now I have replaced 3 glow plugs. I think that some people are afraid to change the system from stock partly due to lack of knowlege on how the GPs work or do not want to mount the switch. However, I have had no problems with the Mercedes relay.

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84 300D, 82 Volvo 244Gl Diesel

Correct, TDIs and any modern diesel for that matter use high pressure injection (common rail or any other technology) to obtain better control over the combustion process thereby increasing efficiency and reducing emissions. These are all DI AFAIK

__________________
For Sale: 1982 MB 300TD
1995 Chevrolet Suburban 6.5TD

Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel

I also use a similar solenoid on my Scout to get more current (individual wire to each plug from solenoid).

__________________
For Sale: 1982 MB 300TD
1995 Chevrolet Suburban 6.5TD

Sold: 1980 IH Scout Traveler- Nissan SD33T Diesel

You have part of the Idea. No matter how the fuel gets to the injector a direct injection system injects the fuel directly into the cylinder. There is no sort of chamber (pre- combustion, swirl and so forth; many different types tried). The nozzle ends have multiple tiny hole that the fuel is injected out of so the fuel is atomized better than with a precombustion chamber making it easier to start.
You might do an internet search to get a better idea.
Also the common rail system is actually a very old system but has been updated. In one the old system a hydraulic pump created all the pressure and a mechanical device lifted the injector needle off of its seat and the fuel was injected. How much fuel was injected depeded on how long the needle was lifted off of its seat. Now the computer controls the lifting in the old days it was mechanical.

__________________
84 300D, 82 Volvo 244Gl Diesel

found some interesting info about the Cummins intake heaters... there are 2 separate heater circuits within the unit, each is 12v and each draws 110amps. The heat cycle is only 3-5 seconds, it continues to cycle until the plenum temp or the coolant temp reach a point where the computer determines it is not necessary.


The stock system uses 2 relays(solenoids) and the wiring is 8 ga... not exactly overkill for that amp draw, but I suppose its a pretty short run.


The power draw is large enough to damage the alternator, so the computer actually 'disconnects' the alternator from the system before/during the on cycle of the heating element. Some have seen their voltmeter go down to 8volts when the heater first cycled on.

This is all info gleaned from various internet sources and is hopefully more or less accurate.

__________________
Cheers,
Robert