Full throttle, specific speed tests in internal combustion engine diagnostics

In the method of making speed-regulated measurements of parameters of an internal combustion engine while the engine is operating under open throttle conditions, the steps of:

• operating the engine with the throttle wide open and allowing the engine to accelerate from idle to its maximum unloaded speed;
• continuously monitoring the speed of the engine by sensing a speed indication derived from a moving member on said engine;
• continuously comparing the speed indications as provided with test speed indications indicative of speeds at which the parameter of the engine is to be measured;
• and
• measuring the parameter of said engine in response to said comparisons indicating that the speed of the engine has reached the corresponding test speed.

Apparatus for testing an internal combustion engine while operating under open throttle conditions without the need of a dynomometer, comprising:

• a fuel pressure transducer means disposed downstream of the throttle in the fuel pressure system of said internal combustion engine;
• speed sensing means adapted to be disposed to sense rotation of the engine under test through an angular increment which is substantially less than a revolution of the engine as related to time in a fashion to provide an indication of speed on a sub-revolution basis;
• and
• processing means responsive to said speed means and to said transducer for successively monitoring the speed indications provided by said speed sensor means and the output of said transducer as said engine is accelerating and for determining in response thereto the speed at which the pressure in the fuel system is maximum.

In the method of making speed-related measurements of parameters of an internal combustion engine fuel system, the steps of:

• operating the engine with the throttle wide open and allowing the engine to accelerate from idle to its maximum unloaded speed;
• determining the maximum fuel pressure of the engine as it accelerates;
• and
• sensing the speed of the engine at which maximum fuel pressure is sensed.

In the method of measuring fuel pump inlet restriction of an internal combustion engine under full fuel flow conditions, the steps of:

• operating the engine with the throttle wide open and allowing the engine to accelerate from idle to its maximum unloaded speed;
• continuously monitoring the speed of the engine by sensing a speed indication derived from a moving member on said engine;
• continuously comparing the speed indications as provided with a speed indication indicative of substantially the maximum rated speed;
• and
• measuring the pressure at the inlet to the fuel pump of said engine in response to said comparisons indicating that the speed of the engine has reached substantially the maximum rated speed.