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chillwill · 08-10-2015, 10:15 AM

I have a 2001 Alpine Coach, ISC 350 8.3 engine. I noticed about 2 or 3 months ago i was seeing black smoke coming from my exhaust. The engine runs okay with no engine check light on. Every time there is a hard acceleration or going up a incline I get the black smoke. Took it to Cummins and they replaced a cracked manifold and my turbo. No luck with that. Cummins tech told me I needed to run the coach because it may be backed up with soot. No problem. Had already scheduled a trip out to Vegas about 1700 miles but no luck. The issue still exist. After during some research online and looking at other folks that had the same issue, it could be my Charged air Cooler (CAC) or the exhaust is stuck closed. A bad injector was ruled out because it will cause the check engine light to come on. Any help will be greatly appreciated.

mel s · 08-10-2015, 10:28 AM

Quote:

Originally Posted by chillwill

I have a 2001 Alpine Coach, ISC 350 8.3 engine. I noticed about 2 or 3 months ago i was seeing black smoke coming from my exhaust. The engine runs okay with no engine check light on. Every time there is a hard acceleration or going up a incline I get the black smoke. Took it to Cummins and they replaced a cracked manifold and my turbo. No luck with that. Cummins tech told me I needed to run the coach because it may be backed up with soot. No problem. Had already scheduled a trip out to Vegas about 1700 miles but no luck. The issue still exist. After during some research online and looking at other folks that had the same issue, it could be my Charged air Cooler (CAC) or the exhaust is stuck closed. A bad injector was ruled out because it will cause the check engine light to come on. Any help will be greatly appreciated.

chillwill
The most common causes of black smoke are faulty injectors, a faulty injector pump, a bad air filter (causing not enough oxygen to be supplied), a bad EGR valve (causing the valves to clog) or even a bad turbocharger.
See: Black Smoke: Cause, Impact, and Prevention | HDDEO
Mel
'96 Safari

Jake74 · 08-10-2015, 11:08 AM

Your engine is a CAPS injection pump equipped engine. The injection pump on these engines were known for reliability issues. If it runs smooth and idles fine it's probably ok. If CAC had a hole in it power would be low. I would check the lift pump pressure that supplys the injection pump. Low fuel pressure will cause black smoke and the lift pumps were known to go out. Pressure should be 15psi or so at idle and 8-10psi under load.

Old Scout · 08-10-2015, 06:44 PM

Wow--if they replaced the exhaust manifold and turbo--you have already paid handsomely for it. Seems like Cummins would be willing to work with you until you get it solved. A little black smoke on acceleration suggests fuel issues or air intake. A lot of black smoke with substantial power loss suggests turbo pressure loss [cac or pipe/hose connections]--"assume" Cummins checked for that.....keep us posted.....

Koop · 08-10-2015, 07:14 PM

CAPS era Cummins engines aren't current clean diesels. A puff of black smoke on initial acceleration or when suddenly requesting full power isn't unusual. If it continues to chuff heavy black smoke with a loss of power, there's a problem.

chillwill · 08-11-2015, 07:07 AM

Hello everyone. Everyone seems to be really busy these days to get anything done, especially Cummins. I'm scheduled to take it in to them next week for it to sat until they are able to work it in. I have spoken to some other techs in the area and they mention the CAC or exhaust brake. I'm getting ready to check out the exhaust brake to see if its stuck closed. The coach runs fine. I drove it over 3400 miles during the month of July and the only issue I had was black smoke coming from the exhaust during hard acceleration or going up hills. On level road, no smoke. I was also told that if the check engine light is not on, I can rule out the injector issue because it will cause it to come on.

Jeff and Cheryl · 08-11-2015, 11:52 AM

Chillwill,
Have you changed the air filter. With mine, when the AF gets a lot of dust in it, I'll get black smoke as you describe, in the same situations you are describing.

chillwill · 08-12-2015, 06:21 AM

The air filter was the first thing that came to mind. I did change it out but still had the same issue.

D Lindy · 08-12-2015, 09:44 AM

Could be that one or more of the rubber sections of the piping for the air intake system are weak and collapsing when there's a call for extra air flow, thus restricting the air causing a rich burn condition. There are 1/2 a dozen of these rubber pieces between the air cleaner, Charge Air Cooler, and the intake manifold.

chillwill · 08-12-2015, 07:40 PM

I got underneath the coach and checked everything that I could. Nothing noticeable to me or that I could see. Thanks for all of your inputs. I'm taking it back to Cummins next week and have them see what they can find.

Mule Skinner · 08-14-2015, 05:04 PM

Try changing the fuel filter. Can't hurt.
I have had power loss twice. Both times I had lots of smoke. The first time I took it to a cummins dealer and had the entire fuel system checked. Fuel Filter was all I needed.
At your own risk,
I add red line deisl full additive directly into the filter about a quarter full. Then top off with fresh diesel fuel bufore installing. This I learned from a friend who is a deisl mechanic.
The only place I can find the red line additive is summit racing in Reno nv. They will ship it to you.
I buy it by the case and add it to my tank every fill up.

chillwill · 08-15-2015, 08:03 AM

The fuel filter was the second thing that I checked and changed out. Whatever my issue is it has to be something simple that I can't figure out. Like is said earlier in this post, the coach runs fine.