Diagnosis apparatus for self-propelled vehicle

A diagnosis apparatus suitable for use on a vehicle which has an engine mounted thereon and which can convey a loaded material, said diagnosis apparatus comprising:

• engine rotating speed detecting means, for detecting a rotating speed N of the engine;
• fuel injection amount detecting means, for detecting a fuel injection amount q per rotation of the engine;
• loaded weight detecting means, for detecting a weight W of the loaded material;
• vehicle speed detecting means, for detecting a speed V of the vehicle;
• trigger signal oscillating means, for oscillating a trigger signal d per predetermined time period to;
• and
• calculating means, which receives a detected rotating speed N from said engine rotating speed detecting means, a thus detected fuel injection amount q from the fuel injection amount detecting means, a thus detected weight W from the loaded weight detecting means, a thus detected vehicle speed V from the vehicle speed detecting means, and a trigger signal d from the trigger signal oscillating means;
• which calculates a time period t (=n·to) for which the rotating speed N and the fuel injection amount q are maintained substantially at their same values on a basis of a number n of the trigger signal d;
• which calculates an accumulative total fuel injection amount Q (=Σq·N·t);
• and which calculates at least one of a fuel injection amount q1 (=Q/Σt) per unit time and a conveying amount w1 (=ΣW·V·t/Q) per unit fuel injection amount.