Black Smoke

[DAYSU]

First thing I want to say is this sight is great!!! I should of joined a year and a half ago when I got my first diesel.
Anyway, I have a 95 6.5 TB in a 28 ft. 16000# motorhome. I built a shroud to help cooling and it really helped! I went on a trip a month ago to Phoenix through some goooood mountains and all of a sudden I am blowing out black smoke under load. Got back from trip, found vacuum hose to vacuum canister was off. Contacted mechanic, had codes checked, all were great. Memory code showed vacuum problem to turbo. He reset codes. Next day took MH out, still had black smoke but when I stopped found hose was off again. Re-installed hose. Next day drove it to dump tanks, STILL had black smoke under load. Only other thing I did was increase size of air intake from 3" to 4" to new air filter(K&N) Engine starts and runs great. Gas mileage on trip to and from Phoenix sucked!!!

Any ideas, help, etc.
Thanks,

Note: Mileage is 85000. New heads/valves and PDM computer chip for injectors replaced at 78400 miles. Fuel and air filters replaced.

[DmaxMaverick]

Black smoke means overfueling. In your case, because of an open wastegate. If you have no vacuum to the wastegate controller, the boost drops off, but the fuel doesn't. Symptoms are black smoke, power loss, higher EGT's, lower mileage, and overheating.

You need to find out why the hose keeps coming off. Is it loose, is it getting vibrated off, or is something putting a strain on the hose? No matter which, the hose should be replaced with the proper size and length, ensuring it is not being pulled off by some other source such as engine torque or high velocity air (could the shroud you installed be "blowing" it off?). The connections should be snug.

Good luck with it.

[CareyWeber]

Does your turbo spin freely?

[DAYSU]

Thanks for your replies. I found the problem!! The other end of the vacuum hose connected to a plastic tube going to something on the left rear of the engine, about an 1/8" size, was off. Put it back on and, FIXED!!!!

Thanks, all!