Glow plug tip

JClark · Feb 28, 2004

The senior mechanic at my dealer learned a new trick at JD tractor school and passed it on to me. To make starting a 4000 series tractor easier in cold weather put the range selector in gear and turn the key to the start position and hold it there for 5 seconds or so. The glow plugs only come on when the key is in the start position and the safety interlock will keep the engine from cranking. You could use the PTO switch too.

This works great on my 4110. Cold starts in cold weather usually entail a few seconds of cranking followed by lots of smoke and really rough running. By holding the key in the start position for 5 seconds before cranking the glow plugs have a chance to get hot and the engine starts immediately with practically no smoke.

Apologies to those who already knew this trick.

thcri · Feb 28, 2004

Your glow plugs only come on in the start position?? I guess I can't say I have ever seen that cause usually you do have to let the plugs warm up first. My New Holland's both have a position before the starter position with a light to let me know the plugs are energised. In colder weather I have to have them on at least ten to fifteen seconds before engaging the starter. I can't imagine hitting the starter at the same time the plugs get energised you would get any place on starting.

murph

frank_f15 · Feb 28, 2004

same here on my kubota, seperate position just for glow plugs, with indicator light.

RoyJackson · Feb 28, 2004

On my Deere 670, one must turn the key counterclockwise to actuate the glowplugs...hold for 5 to 10 seconds (you can hold it as long as you want to...I use 10 seconds normally), then clockwise to start the engine. The counterclockwise position is spring loaded...one must hold it in position or it rotates back to the Off position.

The larger 4xxx series uses a heated air intake system (don't know a thing about that) and the manuals don't even mention glow plugs.

The 4110 manual reads:

 10. Allow the glow plugs to preheat the engine. After approximately three seconds listen for a click. Engine is now ready to start.


The 43xx manual states:

 10. For cold weather starting, use the intake air heater system. Activate the intake air heater system by pushing in the ignition key switch with the key, and holding it there for the required time:

· 10 - 15 seconds for temperatures as low as -18° (0°F).

· 15 - 30 seconds for temperatures below -18° (0°F). 

So, it appears the 4110 series machine's glow plugs are on a timed circuit. it appears by enabling one of the safety interlocks and turning the key to "start", that extends the time the plugs are on (since the engine won't crank while the interlock is enabled). However, next time you start your 4110 using the method described by the senior mechanic, listen for that "click" described in the 4110 manual. If it clicks after 3 or 4 seconds, the "better" starting may be more psychological then real.

I dunno...seems like my 13 year old 670 might have a better glow plug system...just a bit more work.

yellowsocks93 · Feb 29, 2004

The 4210-4710 use the air heater system and so do the 790 and 990. Your correct on how to work both types. I also don't really know how the air heater works but I know not to use ether to aid in cold weather starting or there could be an explosion according to the manual.

RoyJackson · Feb 29, 2004

"not to use ether to aid in cold weather starting or there could be an explosion according to the manual. "

Back in the late 60's, I ran a Ford backhoe for a year. There was a place on the dash you could insert a can of ether. All you could do is give it one shot at a time.
The danger with using ether down an intake is using too much. Even using a little could cause a backfire on a gasoline engine. With a diesel's high compression, you could blow the head off.
If you got to use it, a little whiff is all you want to use...just enough to get the engine turning.

For we residential owners, there is no need to even consider using ether. Bring the tractor inside the garage or use that block heater. The machines (like your 990) using a preheater in the intake system probably have an exposed heater element (sort of like the burner on an electric stove). Using ether in a system like that or with automatically actuated glow plugs (as described on the 4110 tractor) would ignite the ether. Not a good thing there, friends... The ether should be ignited by the engine compression..that's the whole idea behind using it.

In a more rural (farm) environment, or at a construction site...might not be any other option since electricity isn't always available in the field. When I was operating that backhoe...wasn't too uncommon to see a small fire ite underneath some of the equipment (dozers and such). That was done to heat the oil so the equipment would start. How's that for a block heater?

But, if you have to use it...just a whiff, no more!

RalphVa · Feb 29, 2004

Wonder why JD went to glow plugs? My neighbor's old 1950ish diesel JD starts at the first turn of the key to start, instantly, no matter it had sat unstarted all winter. It's direct injection; I guess. Smooth running engine, too.

Ralph

RoyJackson · Feb 29, 2004

"Wonder why JD went to glow plugs?"

I've never seen a diesel without glow plugs, but my experience doesn't go back beyond the mid 60's.

I suspect the mid-50's Deere had lower compression, thus easier turning of the engine. Also, VA doesn't get that cold most of the time. That old tractor probably has a huge flywheel as well. That would account for the smooth running.

But didn't some of the old Deeres have a small gasoline powered starter engine?

Bird · Feb 29, 2004

( I've never seen a diesel without glow plugs, but my experience doesn't go back beyond the mid 60's )

I'm not sure, but I think there are actually quite a large number of them without glow plugs. I think perhaps there are some different names used by different manufacturers, but one system is an electric heating element in the air intake (still have to hold the key, or another switch, for awhile to get it hot before attempting to start). That way the air going into the cylinders is hot enough to light off the engine. That's what the old Oliver I used baling hay had. And I've driven two trucks; one a GMC and the other a Freightliner, both with CAT engines that I don't think had glow plugs; instant start just like a gasoline engine. even cold. But they had an automatic injection system to inject a squirt of starter fluid (ether?) when you hit the starter.

JClark · Feb 29, 2004

On my 4110 the glow plugs only stay on about one second when I turn the key to the on position. I am judging this by the solenoid click I hear and the indicator lights getting brighter. The sequence seems to be:

Turn key, fuel valve and glow plugs solenoids click on
One second later glow plugs solenoid clicks off, lights brighten

On my tractor that one second of glow plug heating is not enough to make for an easy cold start in cold weather, which in my world in anything under 50 degrees.

In the 4000 series everything above the 4110 has direct injecting which makes a difference in starting behavior.

My old 950 had an intake preheat but it never needed it.