Engine start question...

[Geom]

I've got a question about engine starting and what should be considered "normal".

Once our engine starts, it runs like a champ dog and has a distinctive "healthy" rumble/sound.
Lately, however, when I've started it, it lugs a bit, smokes a bit, then within I'd say 10-20 seconds it "clicks" (not an actual click, just flips over) and then runs great and sounds great, as expected. So I'm concerned if this is indicative of something needing more attention, or something to expect with these babies.

This seems to be happening in "cold" weather starting (below 50 at night type weather), but not freezing. It did not exhibit this behavior in the hot or cool/warm weather.
This is also after it had been sitting for a few days (or even weeks). Once it's started, however, I can shut it down, and restart hours later and everything is fine.

I realize these beasts can require a bit of time to grumble fully awake. I just want to make sure that's all this is and not something more needing of attention.
Your thoughts are appreciated.

P.S. This is kind of what triggered the other question about an oil additive.
So in followup to that, I'd be curious what the thoughts are on cold weather starting and starting after a long idle time and how to best protect these engines.

Thanks in advance,
George

[sparkplug188]

Is this what you are describing?  It is normal.

Detroit Diesel 6v92TA Cold Start: http://youtu.be/RNbM8AOyDLA

Mine does the same thing. It starts and runs smooth on the first revolution when the average temperature is above 50.  Any colder than 50 causes it to sputter and miss for 5-10 seconds, followed by a rolling idle for 10-20 seconds, then it quickly transitions to a smooth idle.

[bevans6]

Probably the biggest contributor is the low compression of a turbo motor.  Natural engines seem to settle into an idle faster.   I've noticed that my engine is quite smoky and rolly for the first 10 - 15 seconds.  I find that giving it a bit of throttle helps get past that, but I think I have my idle set too low.

Brian

[lostagain]

Same with mine. I find that if I turn on my electric priming pump for a few seconds before starting, it helps noticeably.

JC

[Geom]

@Sparkplug, yeah pretty much how it sounds, although nowhere near as pronounced as that (video). It's just a bit of a lug, then with one last puff of white smoke, runs perfectly.

@brian, I've been hesitant to give it throttle right after cold starting it after a long idle, figuring I'd give it time to get oil moved around in all of the right of the right places, before adding additional stress (by adding throttle), until it's warmed up a bit. Does that matter?

@JC, I don't think I have an electric priming pump, or if I do I have no idea how it's operated

[bevans6]

I'm talking about raising the running speed from around 550 rpm to maybe 650 - 700 rpm, or just enough to take it off the idle circuit, for about 30 seconds.  I also find that doing the same thing helps it actually start.  when I pull the blower off to install my aftercooler I will obviously do a complete tune up, including resetting idle speed and the starting aid.  Idle speed is a total pain on an MCI install like mine, it's covered up with the throttle mechanism plate.

Brian

[eagle19952]

why good batteries help...and your engine is in better shape than you think...takes a lickin and keeps on tickin...

https://www.youtube.com/watch?v=y-D2AX53VPk

[Jim Eh.]

If it is just for an intermittent run up you could plug in the block heater before a start up for 15 - 30 minutes before a start up to reduce or eliminate the smoking/surging.

[TomC]

You maybe loosing fuel prime. Listen to this Youtube of the Big Bud 747 with its' 16V-92TTA starting. It is classic loosing fuel prime. Wants to start, but then you have to crank it for a bit to get the fuel back in the engine. Don't quite understand why they don't fix that. https://www.youtube.com/watch?v=OjDshU8pDxI Good Luck, TomC

[eagle19952]

Be prepared ...  
fixed

https://www.youtube.com/watch?v=3NRaqgab0_w

[HB of CJ]

This only works if you have an older MUI, (mechanical unit injector) non electronic 2 stroke Detroit with the old fashioned "PULL TO STOP" manual shutdown lever to shut off the engine.  You know ... the old kind you need to return to the pushed in position to start the beast.

We always left the shut down lever in the "OUT" or "SHUT DOWN" position after the engine was shut down.  This was a local custom.  Fire department long ago.  Then if the mighty Detroit was cold and the weather temperature was cold, we would leave our foot off the throttle ...

... and just start and spin the Detroit for about 10 seconds to build up some heat in the cylinders.  THEN we would crank while pushing IN the shut down lever, fueling the engine.  Seemed to work just fine.  If the engine did not start the first try, do it again.  Good batteries required.  We did not use starting fluid.  HB of CJ (old coot)

[luvrbus]

They are all that way spin let it set spin again they fire,the turbo model have a starting aid adjustment to retard the timing to build heat.
The clicking he hears are the rocker arm and valves once they cover with oil it stops he may need a valve adjustment also 

[akroyaleagle]

Great videos guys!

Geom,

If you live where it gets cold, install a block heater, it will make life simpler.

Cold starts on DD 2 strokes make your heart weak.

If you crank your engine like the first video, expect to buy a starter soon. 30 seconds is not as long as you might think but the starter will get pretty hot doing that. The starter in anything needs a cooling period after cranking like that.

Your engine should start immediately when the button is pushed. If it doesn't it may be getting weak. In cold weather use the block heater. It will then start immediately again.

I have seen other buses started that cranked a long time in my opinion, then loped for a while. the owner said it had always done that.

Makes me shudder.

[eagle19952]

speaking of shudddering..

in the arctic...you would shudder to know the amount of ether that gets sprayed into diesel engines....especially Detroits.
never hurt a thing.
except the 7.3 liter Fords... they had a air preheat switch in the air cleaner....blew the housings to smithereens....

[akroyaleagle]

Seen a lot of that too Don.