Vehicle engine pulse stream analyzer

• US 6,667,622 B1
• Filed: 05/03/2001
• Issued: 12/23/2003
• Est. Priority Date: 05/03/2000
• Status: Expired due to Fees

• Current Assignee: Peter J. Lenehan
• Original Assignee: Peter J. Lenehan
• Inventors: Lenehan, Peter J.
• Primary Examiner(s): Patidar, Jay
• Assistant Examiner(s): Lair, Donald M.
• Application Number:
  US09/847,928
• Time in Patent Office: 964 Days
• Field of Search: 324/378, 324/380, 324/381, 324/382, 324/384, 324/388, 324/391, 324/392, 324/402, 324/379, 324/115, 701/29, 701/101, 701/103, 701/102, 701/33, 701/99, 731/173, 731/19.A, 123/294, 123/296, 123/305, 123/478, 345/440.2, 345/10, 340/660
• US Class Current: 324/384
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 41/1441 Plural sensors
• CPC Class Codes: F02D 41/1446 the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/1474 by detecting the commutation time of the sensor
• CPC Class Codes: F02D 41/1475 Regulating the air fuel ratio at a value other than stoichiometry
• CPC Class Codes: F02D 41/1481 Using a delaying circuit
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02P 17/12 Testing characteristics of the spark, ignition voltage or current testing of sparking plugs H01T13/60
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A low cost, easy to use, hand held pulse stream analyzer is designed to show, after an engine stops operating, which pulse stream, ignition or injection, quit first. Additionally, the analyzer is capable, using relative time domain analysis to comparatively analyze these pulse streams to the alternator ripple pulse stream, of determining if the fuel flow to the injectors quit, thus causing the engine to quit. This information quickly gives the technician a direction to investigate to find a responsible faulty component for the problem being experienced, and is especially helpful in attempting to diagnose intermittent faults in a much more efficient manner. The inventive device is usable on virtually all brands and types of gasoline powered vehicles.

Claims

1. A pulse stream analyzer for use in diagnosing the cause of vehicle engine failure, said pulse stream analyzer comprising:

a first circuit portion for processing a ripple signal from an alternator of said vehicle to provide a digital pulse stream representing said ripple signal, which provides an indication as to whether said engine is operating;

a second circuit portion having a capacitive ignition pickup for providing an ignition digital pulse stream;

a third circuit portion having a magnetic injector pickup for providing an injector digital pulse stream;

a first AND gate for receiving a logic signal derived from said ignition digital pulse stream;

a second AND gate for receiving a logic signal derived from said injector digital pulse stream; and

a latching element.

2. The pulse stream analyzer as recited in claim 1, and further comprising a housing having a keypad, said keypad having a plurality of keys and indicator lights disposed thereon.

3. The pulse stream analyzer as recited in claim 1, and further comprising means for applying an equal delay to each said digital pulse stream to produce said logic signals.

4. The pulse stream analyzer as recited in claim 3, and further comprising a driver which enables a “

FUEL QUIT”

indicator if the digital pulse stream representing said alternator ripple signal stops before the ignition or injector digital pulse streams stop.

5. The pulse stream analyzer as recited in claim 1, wherein each of said first and second AND gates comprise four input gates.

6. The pulse stream analyzer as recited in claim 1, wherein the pulse stream analyzer is designed such that whichever of said digital ignition and digital injection pulse streams stops first, while said vehicle engine is operating, a high output is produced at its corresponding gate, causing the other gate to be locked out by said latching element, which in turn activates an indicator related to the digital pulse stream which stopped first.

7. The pulse stream analyzer as recited in claim 6, and further comprising a housing having a keypad, said keypad having a plurality of keys and indicator lights disposed thereon, wherein said indicator comprises one of said keyboard indicator lights.

8. A method for diagnosing the cause of a vehicle engine failure, said method comprising:

connecting a digital pulse stream analyzer to an alternator of a vehicle engine to be tested;

connecting a capacitive ignition pickup of said digital pulse stream analyzer to a spark plug or coil wire of said engine;

placing a magnetic pickup in close proximity with an injector body or throttle body of a fuel injector of said engine;

turning an ignition switch of the vehicle on without starting said vehicle engine and checking to ensure that there is no electrical interference with said analyzer;

starting said vehicle engine and initiating a setup sequence setting a unique delay time interval for the vehicle;

turning said vehicle engine off, to set said unique delay time interval;

starting said vehicle engine again;

activating a reset circuit; and

evaluating a test result indication on a keyboard of said analyzer.