black smoke

[bigred]

Hopefully I can answer all your questions .Yes,10  pounds of boost was running on relatively flat road in forth gear.I have been told to run it in 4th on short hops to exercise this Engine (ht755cr) .I have bought my fuel from a TA truck stop but is probably the same stuff Loves has.Have never noticed the check engine light coming on.And yes ,on a hill the boost will jump way on up .Thanks for all of your replies .Have loved ,drove and been around buses since grade school,but trying to diagnose problems is new to me .My previous experience was check and add oil and changing a fuel filter .Any thing more than that ,I waited on the hook!!! LOL.Of course there is a major difference when you are using your money and not the company's!!!!