Black smoke when accelerating

coloradorich · 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

Flatspot · April 12, 2011, 01:12:45 PM

Black smoke usually means more fuel than air.
LJ

robertglines1 · 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.

luvrbus · 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

Ace · April 12, 2011, 02:36:05 PM

Does it have a turbo?

TomC · 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

rv_safetyman · 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

white-eagle · 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.

luvrbus · 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

coloradorich · 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

luvrbus · 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

Boomer · 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.

babell2 · 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

bevans6 · 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

wal1809 · 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.