Lots Of Smoke When Trying To Start...

[Highway Yacht]

Seems like there have been a lot of "Smoking" post lately so I might as well get mine in too.. I've got an 8V71T in my MC-9. The other day I went out to start it to make a short trip. The engine spun over several times without firing. I noticed in my mirror that it looked like a huge cloud of white / grey smoke floating around at the exhaust. It didn't look like your regular smoke since it seemed to hug the ground like fog instead of thinning out real quick. I spun the engine over again and the smoke just poured out and it still didn't fire. I walked to the back of the bus and it looked like a fog was coming out the exhaust tip. While at the back of the bus, I could smell a strong diesel fuel smell in the smoke. It fired on the 3rd try and the smoke cleared up almost instantly. I made my trip with no problems and no signs of smoke while idling or driving... only while trying to start it.  I let it set 3 days and went out to start it again and it is doing the same heavy diesel smell smoking and not seeming to fire. It will eventually fire after several attempts and once again the smoke clears out as soon as it starts. The temps were around 48 to 50 degrees both times. Can a diesel flood?? If so, what would cause it to flood??? Any other ideas???

Jimmy

[robertglines1]

has happen to me when I last fueled in summer then started in cold weather.In our part of the country they go to a winter blend Oct 1st each year. Like you once started it quit. Haven't noticed problem when the tank has the winter blend in it. FWIW  Bob

[HighTechRedneck]

That is very common for these old engines in cool weather.  The white smoke is from unburnt fuel.  You may have also noticed that initially the engine wasn't sounding as smooth as usual, then it smoothed out and the white smoke stopped, in your case "almost instantly".  In some cases it can take a little longer to smooth and clear.

[luvrbus]

Only takes a few degree drop to affect the smoke on a 8V71T as they are lower compression than  N/A

good luck

[gus]

You have explained exactly what happened the first time I had to start my 671 in 29* weather when I first got it, even to the number of tries!

I smoked out a whole RV park, they even allowed me to return the next year!

I suspect my 671 was tired and was part of its being hard to start.

The 8V71 in my 4107 starts right up in weather down to the 20s but it is fairly newly O/H.

[MARKMC7]

my 8v71 does the exact same thing on cooler days, but just like ole faithful when she fires she runs smoke free from there on.

[Highway Yacht]

Great... Sounds like I don't really need to worry too much then. I had never seen that much smoke coming from anything that wasn't running. Merry Christmas to All...

Jimmy

[bobofthenorth]

Jimmy what you saw was SOP for those of us who occasionally have to start a diesel in a lot colder weather than what you were experiencing.  What I generally do in that situation is to crank it a few turns and then let it sit.  The technical term is "heat soaking".  Let it sit for about a minute and then try it again.  If it doesn't light right off let it sit again.  The absolute worst thing you can do is grind it over for long periods.  All that will do is get you acquainted with how heavy your starter really is.  In cold weather everything is working against you:
- compression is down
- oil is thick so its harder to crank
- battery efficiency goes down so it doesn't spin as fast

[RJ]

Jimmy -

As mentioned above, "heat soaking" is a good way to get the DD to fire in cooler weather.  5 - 10 seconds on, 30 -60 seconds off, repeat.

Or, a couple of hours of having your block heater plugged will make it a happy camper, too!

FWIW & HTH. . .

[white-eagle]

I'm with the last suggestion.  Block heaters are great.  plug it in an hour before you want to leave.  Starts right up, but the smoke will still be there, just not as long.  mine really smokes when cold.

i find the block heater works best, but a shot of ether will help if the block heater didn't or momma wants to leave sooner.  just a quick shot, don't soak down the filter.  mine kicks right in, but  stay upwind to avoid the smoke.

Yours does not sound unusual.

[MikeH]

... but a shot of ether will help if the block heater didn't or momma wants to leave sooner.  just a quick shot, don't soak down the filter.  mine kicks right in, but  stay upwind to avoid the smoke.

Yours does not sound unusual.

Warning, stupid question ahead: where do you put the ether? I am not a diesel guy and have no bus yet. On an older gas engine I would expect to take the air cleaner off and put it in the carburetor, but no such thing with fuel injectors. What would I be looking for? If you are talking about putting it in where the air filter is, does it matter which side of the filter you put it in?

Thanks,
Mike

[JWallin]

Ether isn't the nicest thing you can do for your Detroit. If you need to leave earlier, it will be much happier if you turn on the block heater sooner.

[bobofthenorth]

In 7+ years of ownership I think I've fed our noisemaker ether maybe twice.  Diesels tend to get addicted to ether if you use it enough ........... but enough with the thread drift, that's a subject that gets well thrashed out - check the archives.  As to where you put it, you can dump it in ahead of the air cleaner but on my bus there is a port directly into the intake after the cleaner. Heat, good batteries and time are your friends - ether is not your friend.

[bevans6]

I have found that you can avoid a lot of the white smoke if you start from the back, and hold the engine stop lever closed while you do the "heat soaking" spins.  The heat is derived from compression, the white smoke is from unburned fuel, so if you activate the engine stop lever you inject no fuel and compress only air.  I then roll off the stop lever while cranking and usually it starts up smooth.

Didn't  think of this myself, got it here from the masters!

Brian

[luvrbus]

Very little ether in today's starting fluid not like it was in the past when it was 90% and fwiw your 2 stroke mechanical has a starting aid adjustment (pita to set) the DDEC's do it by electronics 


good luck