Cold starts: what is your preferred RPM setting??

[Flintknapper]

In cold weather season, when parking the tractor after usage to shut it down, I set my idle a bit higher than low idle - usually 1250 - 1300rpm, then shut it off.

Then after it cools off, maybe the next day, it will be preset at a good start and warmup idle rpm. 5 - 10 seconds of glow, depending on temperature, and fires right away when cranked.

Smart. Hadn't really thought of that, set the next days 'start up' idle when shutting down at last use.

Think I'll do that too.

 

[nbryan]

Smart. Hadn't really thought of that, set the next days 'start up' idle when shutting down at last use.

Think I'll do that too.

It's been working for me for years now, become a habit.

 

[Flintknapper]

It's been working for me for years now, become a habit.

Employed it just today. Needed the tractor to push an old cut down stump out of the way and remembered to set the idle at about 1200 rpm before shutting it off. Such a simple thing to do.

Previously, I'd just blindly guess at the throttle position and then immediately adjust it upon start up (either it was high or too low). My engine has a 'sweet spot' on start up where it runs most smoothly and that happens to be about 1100-1200 rpm.

Don't know why it didn't occur to me to just set it at that rpm upon shut down, but sometimes its the simple things that escape us. Thanks for posting your method. I will use it henceforth.

Flint.

 

[BobInSD]

thanks.... I put on more hours when colder than -20F than hours above 50f.

unfortunately the pre-heat tables in the manual do not go to the temps we get around here during snow blowing season. Regardless I give my glow plugs lots of time to make their work. Probably more time than most I am guessing. I don't rush them.

I noticed that. I was getting ready to ask for the bottom half of the chart. The chart for warming up the HST is similar. It bottoms out around 1/2 hour but way above my typical temps.

In my case when winter cold is here (no I don't mean Texas or Florida winter cold but Canada / Minnesota cold) starting with throttle pulled all the way back to min. means I have to hit my starter probably more than once maybe 2 or 3 times but when started at throttle set at 1,400rpm or a little lower it starts up first hit of the starter.

That's about what I do, summer or winter. I'll try to start at idle when it's warm again. I've still got a "gasoline" mindset and need to start thinking "diesel".

Thanks,

 

[T0adman]

I frequent a truck forum and see that so many think that a block heater is only about getting it started. Others think that it is for their personal comfort by getting quicker heat to the cab. A block heater is for the good of the engine and using it as you described is the correct plan.

What temp should I start using my block heater?

 

[mdhughes]

I have a L3901 and when I start it when it is really cold, it idles itself up till it starts to warm up.

 

[GeoHorn]

I just follow the manual. Roughly 1200 rpm and leave it there for a minute or two. Then I'll pull it out of the shop and roll at that same rpm.
You want to get the oil pump moving and some heat in the engine. Starting and "warming up" at idle isn't going to do it as well. My last two trucks would stay on high idle for a minute or three when it's super cold. That's all programmed from the factory. I can't imagine they would do it if starting them with increased idle speed was bad.

They do that to meet EPA requirements on NOx …. which are higher when cylinder-walls are cool…. They‘d rather meet EPA standards so they can sell that vehicle in the U.S…. and aren’t concerned if you have to buy another new car sooner.

 

[The Evil Twin]

They do that to meet EPA requirements on NOx …. which are higher when cylinder-walls are cool…. They‘d rather meet EPA standards so they can sell that vehicle in the U.S…. and aren’t concerned if you have to buy another new car sooner.

Eh, not really. You are right about the temperature of the cylinders but it's not about emissions. It's about keeping wall washing down- fuel condensing in the cylinder walls and ending up in the crankcase. It also reduces the lubricity of the oil on the piston rings. Diesel and gasser do the same high idle for the same reasons.

 

[GeoHorn]

Eh, not really. You are right about the temperature of the cylinders but it's not about emissions. It's about keeping wall washing down- fuel condensing in the cylinder walls and ending up in the crankcase. It also reduces the lubricity of the oil on the piston rings. Diesel and gasser do the same high idle for the same reasons.

My comment was a virtual direct-quote from my Chrysler manuals. With modern fuel injection there is little/no chance of excess fuel washing down cyl-walls…and it’s certainly not likely with Top-of-compression-stroke diesel injection.

Here’s a link which may further support: https://www.autopadre.com/blog/why-does-my-car-idle-high-when-i-start-it

 

[lynnmor]

What temp should I start using my block heater?

It is a balancing act in large part. A block heater will cost roughly 20 cents per hour to operate, doesn't sound like much but do the math. If you use a timer, about 3 hours is enough. Whenever the overnight temperatures are well below freezing, I would use it. Battery size and condition, type of oil and viscosity, plus other factors all enter into the equation.

 

[MapleLeafFarmer]

It is a balancing act in large part. A block heater will cost roughly 20 cents per hour to operate, doesn't sound like much but do the math. If you use a timer, about 3 hours is enough. Whenever the overnight temperatures are well below freezing, I would use it. Battery size and condition, type of oil and viscosity, plus other factors all enter into the equation.

X2 and will add that experience is your friend on this one as well.

I have newer well sealed but unheated storage building (no drafts) and at -30f a couple hours and my newer Kubotas start fine / more than a couple of hours and not much difference noticed.... If stored outdoors though and windy!!! well that a whole other story where plugged in for 1/2 day with quilted blankets over the bonnet etc.. is needed (haha)

on the plus side we only pay 8 cents / kw for electricity part of the bill so even cheaper to run.

 

[nbryan]

What temp should I start using my block heater?

These small 3 cyl 1- 1.5L engines heat up pretty fast once the block heater is plugged in. I'm used to 2 or 3 hours to prewarm our car block, but find that even one hour makes a big difference for starting my tractor's D1305 1.3L engine.
I plug in starting around -10C.

 

[DustyRusty]

My BX23S idles at 1400/1450 and you can't get it down any lower unless you tinker under the hood with the settings. My old BX22 idled at 650/700 and always started easily when it was -10* Fahrenheit. That is if I remembered to plug in the block heater. In the winter using the block heater on the BX23S, it also starts quickly but it sounds like it is screaming to me. I can't understand why they set the idle up so high on the newer tractors. I would love to knock it down a little, but I don't know how.

 

[RalphVa]

The startup on the Isuzu generator driver is automated. Has to start and run at same spend and to load up immediately. Guessing rpm is around 1600-1800. A little gem. Starts with no smoke, no clatter, no shudder. Sounds like a gasoline engine. It has a relatively long glow plug time, probably 6 to 10 seconds.

 

[Fordtech86]

Here’s a link which may further support: https://www.autopadre.com/blog/why-does-my-car-idle-high-when-i-start-it

IAC valves, air injection pumps, what the hell is a carburetor? think that info maybe be 20 plus years past it’s prime

but they do have programmed strategy to get engine and converters up to operating temp as quickly as possible for emissions, durability, and driver comfort…