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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: coloradorich on April 12, 2011, 01:07:09 PM

Title: Black smoke when accelerating
Post by: coloradorich on April 12, 2011, 01:07:09 PM
 Well, we're on the road after fixing the air leaks and now a new question.  Never had Black smoke when accelerating before.  Some blue usually when first taking off, but this time black and it continues.  Yes, it's an old bus and previously when the engine would lug it would smoke, but always stopped as I changed gears.  Now, today, with the slightest acceleration it smokes.  We have been sitting for 3 months.  When we bought it in 2003' were told the engine had been rebuilt 60,000 miles prior to us buying it.  Would have to go thru paperwork to find what the hub meter read at that time, but think it was 360,000+.  We've put on less than 50,000.  We spent 3 wks at Luke's a year ago fixing stuff.  Billy went over the engine then, fixed some oil leaks and said it was a good old engine.  Anyway, suggestions?
Rich Murphy
Title: Re: Black smoke when accelerating
Post by: Flatspot on April 12, 2011, 01:12:45 PM
Black smoke usually means more fuel than air.
LJ
Title: Re: Black smoke when accelerating
Post by: robertglines1 on April 12, 2011, 01:18:35 PM
ck reset flapper on blower it might be partial closed.  first ck air cleaner-do you have a flow gauge? it would be green to yellow   red  clogged. If you have oil bath ck for blockage   bird nest   stray  walmart bag    muddobber  nest  ect.  Good time to add what type of bus you gave to your signature.
Title: Re: Black smoke when accelerating
Post by: luvrbus on April 12, 2011, 02:03:05 PM
Have you changed locations the higher the altitude the more black smoke they start around 2000 ft above sea level

good luck
Title: Re: Black smoke when accelerating
Post by: Ace on April 12, 2011, 02:36:05 PM
Does it have a turbo?
Title: Re: Black smoke when accelerating
Post by: TomC on April 12, 2011, 04:03:58 PM
If you have a dry element air cleaner-get a new one.  If you have oil bath air cleaner-clean them.  Black smoke means lack of air-which usually means a dirty air cleaner.
Good Luck, TomC
Title: Re: Black smoke when accelerating
Post by: rv_safetyman on April 12, 2011, 04:53:20 PM
You don't have any information about your bus in your profile and no signature. 

My guess is that you have an 8V71 and no turbo.  You are in the 4-6+K feet altitude range as you travel up I-25 in Colorado.  Plus, there are a bunch more hills than you might imagine.  I would expect some smoke when you get on the throttle.

I doubt that it would be the air flap issue (shuts the down in an emergency).  You might not even have one.  If it was a flap, you would have a hard time starting the engine and almost no power.

TomC probably hit the nail on the head.  Probably an air cleaner issue.  Any chance a bird could have built a nest in the intake?

Jim
Title: Re: Black smoke when accelerating
Post by: white-eagle on April 12, 2011, 05:48:47 PM
Quote from: luvrbus on April 12, 2011, 02:03:05 PM
Have you changed locations the higher the altitude the more black smoke they start around 2000 ft above sea level

good luck

that colorado campground is 8500.  does that mean i'm gonna starve for air, and blow black smoke up the hills?  just a quick note, i don't want to steal the thread.  if this gets more than a quick comment, i'll open a new thread if i have more questions.
Title: Re: Black smoke when accelerating
Post by: luvrbus on April 12, 2011, 05:52:19 PM
Your ok Tom the turbo will help but if you lug the engine a little the 8v92 will blow that black smoke like a train lol keep her turning

good luck
Title: Re: Black smoke when accelerating
Post by: coloradorich on April 12, 2011, 07:51:11 PM
I do have an 8v-71 no turbo. Converted from oil air filter at Luke's about 13000 miles ago. Have not set long enough for birds to build

a nest, wrong time of year. Believe that it may be altitude since we are in Colorado above 5000 ft. If that is the case how do I adjust

the fuel mixture? Is it even possible to do it? I have no Manuals for the engine. Where can they be obtained. Also a Parts Manual for

the Bus.  Thanks for all of your help.

Rich
Title: Re: Black smoke when accelerating
Post by: luvrbus on April 12, 2011, 07:56:44 PM
Not much you can do about it Rich without spending big bucks that is the nature of a non turbo engine just keep your foot out of it

good luck
Title: Re: Black smoke when accelerating
Post by: Boomer on April 12, 2011, 08:02:06 PM
Keep it wound up to 2100 on a slack throttle and the smoke will dissapate a lot at altitude.
Title: Re: Black smoke when accelerating
Post by: babell2 on April 12, 2011, 08:07:37 PM
I learned that one on my way back from VA with my 8V71.
Just let up on the throttle and the smoke goes away. More foot doesn't get more speed just more smoke.

Brice
Title: Re: Black smoke when accelerating
Post by: bevans6 on April 13, 2011, 04:26:45 AM
If you're going to stay at that altitude permanently and need to deal with the smoke problem, a turbo will introduce more air and reduce the smoke, or de-tuning with smaller injectors will reduce the smoke.  Smaller injectors would normally reduce the power as well, but at altitude the lack of air is already reducing the power so smaller injectors just prevents an over-rich fuel situation so the power reduction would be less.  Of course, using part throttle accomplishes the same thing for free, I guess...   ;)

Brian
Title: Re: Black smoke when accelerating
Post by: wal1809 on April 13, 2011, 05:46:42 AM
?NOt to derail this thread at all but yall mentioned something about a bird nest and it got me to thinking.  I was working on the bus the other day and I saw a mouse in the barn near the bus.  Later I had the engine running while I was sitting in a chair near the rear bumper under the hood.  I was working on the WVO system.  All of a sudden I heard a very strange noise coming from the engine compartment.  I could not pin point it as my brain wasn't grasping the noise at all.  I was trying to figure it out and all of a sudden it went away, cleasred right up.  It was so fast I didn't have time to figure it out.  It has not done it since then nor never has it done it in the past.  I'll bet you a nickel to a pickle when I get home today I am going to find mouse evidence in the air intake.  I am thinking a mouse got sucked into the turbo.  I have practiced alternative fueling but running on mouse juice is a little extreme for even me.
Title: Re: Black smoke when accelerating
Post by: Melbo on April 13, 2011, 06:03:05 AM
When I had my 8V71 I was impressed how much better it ran in the midwest than in the mountains.

And even with the turbo on the L10 Cummins there is LOTS more black smoke at altitude than when running out on the plains.

I'm thinking just the nature of the beast here.

Melbo
Title: Re: Black smoke when accelerating
Post by: Jerry32 on April 13, 2011, 06:59:03 AM
I know mine will put out some black smoke at high altitudes around 5000 feet but clears up when after the turbo gets boost up. Jerry
Title: Re: Black smoke when accelerating
Post by: eagle19952 on April 13, 2011, 10:19:02 PM
I'm atake my time kinda guy with a desire to clean the pipes once or twice a trip,
that said coming out of Skull Valley AZ to Sedona on 89?  >:( Flagstaff to Santa Santa Rosa :-\.....just feels nice to finally hit the flats west of Amarillo :-*.....I guy can really get some efficiency....without blowin wasted fuel out the exhaust.
try the west side of Yosemite.... :-\
Title: Re: Black smoke when accelerating
Post by: TomC on April 14, 2011, 08:48:06 AM
Black smoke at altitude is the main reason I turbocharged my 8V-71.  Granted on initial acceleration there is a bit more black smoke, but it clears up right away.  Nice to have full power at altitude without the black smoke.  Over 5,000ft I do have just the slightest bit of smoke on full pedal-but just pull up a bit and it is clear.  Plus the extra power is quite noticeable. Good Luck, TomC
Title: Re: Black smoke when accelerating
Post by: Mex-Busnut on April 14, 2011, 01:02:04 PM
Quote from: coloradorich on April 12, 2011, 07:51:11 PM
I do have an 8v-71 no turbo. Converted from oil air filter at Luke's about 13000 miles ago. Have not set long enough for birds to build

So Rich: How many actual miles do you have on the PRESENT air filter element? Anything over 3,000, it is probably time to change it. And if you have been through any dust storms, maybe a whole lot sooner.
Title: Re: Black smoke when accelerating
Post by: rv_safetyman on April 14, 2011, 02:02:32 PM
If you don't have a Filter Minder, you really need to get one.  They are cheap and really tell you when the air cleaner needs to be changed.  One source is:

http://www.ryderfleetproducts.com/ryder/af/ryder/core/content/product/srm/key/U49%20C3550100820/pn/Filter-Minder-Air-Restriction-Gauge-Direct-Mount-20lb/erm/productDetail.do;jsessionid=2DEC2F64FE09778970F26FD71F99B71E (http://www.ryderfleetproducts.com/ryder/af/ryder/core/content/product/srm/key/U49%20C3550100820/pn/Filter-Minder-Air-Restriction-Gauge-Direct-Mount-20lb/erm/productDetail.do;jsessionid=2DEC2F64FE09778970F26FD71F99B71E)

Hope the long URL works.  If not just do a search on Filter Minder.

Our buses are not good on air filters.  The filters are behind the bus wheels and they stir up a lot of dust.

Jim
Title: Re: Black smoke when accelerating
Post by: luvrbus on April 14, 2011, 02:23:39 PM
The problem I have with the minder is no one ever calibrates the thing to the engine make and model people just throw down 20 bucks and screw it in.
A friend of mine had one he bought off Ebay and it was set on 20Hg and he never changed the filter till the 8v71 was barely running and smoking like crazy because the gauge wasn't in the red lol

good luck
Title: Re: Black smoke when accelerating
Post by: JackConrad on April 14, 2011, 02:31:23 PM
Quote from: luvrbus on April 14, 2011, 02:23:39 PM
The problem I have with the minder is no one ever calibrates the thing to the engine make and model people just throw down 20 bucks and screw it in.
good luck

How do you calibrate one of these?  Or do you have to order one for your specific engine?  Jack
Title: Re: Black smoke when accelerating
Post by: coloradorich on April 14, 2011, 08:41:46 PM
Thanks for the info. We have about 6000 since filter change. Looks like its time to check it.

Again thanks for everyones help.

Rich
Title: Re: Black smoke when accelerating
Post by: chart1 on April 14, 2011, 09:19:19 PM
Yes how you set them for specific engines or do you order for application.
Title: Re: Black smoke when accelerating
Post by: lostagain on April 15, 2011, 06:56:37 AM
All the ones I've seen are the same: up to 20 inches water column.

You have to know how much maximum restriction is acceptable for your engine.

Both my 4-71 and my 6V92 don't like anything over 10 or 12". They start smoking more with my foot down, and don't have as much power with an overly clogged filter.

JC
Title: Re: Black smoke when accelerating
Post by: luvrbus on April 15, 2011, 07:17:17 AM
They make different ones than 20 in water column I have a couple of 12 h2o all your washable filters use a different one,me I never used one as they are made to sell filters on a rainy day in Georgia they will show red lol do you change the filter then I think not just another got to have gimmick to me

good luck
Title: Re: Black smoke when accelerating
Post by: uncle ned on April 15, 2011, 07:19:14 AM


If I didn't smoke when i accelerate,I would loose half of my income from killing mosquitos.

uncle ned