Fuel system leak detection

Details Fuel system leak detection Fuel system leak detection

1999-07-06

2000-12-26

Williams, Hezron

Measuring and testing

With fluid pressure

Motor part or auxiliary

73 40, 73 492, 731181, 123518, 123519, 123520, 702 51, G01M 326

Patent

active

061641235

ABSTRACT:
A vehicle fuel system has on-board diagnostics for leak testing with correction for different operating conditions. An electronic control unit (ECU) is arranged to carry out a periodic two stage leak test, when the engine is running. Stage A includes evacuation of the fuel tank, monitoring bleedup and recording the pressure rise dP.sub.-- A over a predetermined period A following increase of pressure to a predetermined value p2. Stage B includes measuring the amount dP.sub.-- B by which the pressure in the tank rises above atmospheric due to vapor generation over a predetermined period B following venting and closure fuel system. The ECU calculates a value X representative of leakage from the difference between dP.sub.-- A and dP.sub.-- B using a scaling factor K. The test duration is adjusted in accordance with measured values of fuel level and ambient temperature to ensure that the measured pressure changes are dependent on leakage over a range of operating conditions.

REFERENCES:
patent: 5267470 (1993-12-01), Cook
patent: 5333590 (1994-08-01), Thomson
patent: 5408866 (1995-04-01), Kawamura et al.
patent: 5467641 (1995-11-01), Williams et al.
patent: 5490414 (1996-02-01), Durschmidt et al.
patent: 5495749 (1996-03-01), Dawson et al.
patent: 5542397 (1996-08-01), Takahata et al.
patent: 5675073 (1997-10-01), Otsuka
patent: 5679890 (1997-10-01), Shinohara et al.
patent: 5696317 (1997-12-01), Rychlick
patent: 5726354 (1998-03-01), Nomura et al.
patent: 5739421 (1998-04-01), Iochi et al.
patent: 5750888 (1998-05-01), Matsumoto et al.
patent: 5765121 (1998-06-01), Schwager et al.
patent: 5817925 (1998-10-01), Cook et al.
patent: 5878727 (1999-03-01), Huls
patent: 5898103 (1999-04-01), Denz et al.
patent: 5955658 (1999-09-01), Wallrafen
patent: 5964812 (1999-10-01), Schumacher et al.
patent: 6016690 (2000-01-01), Cook et al.
patent: 6044314 (2000-03-01), Cook et al.
patent: 6073487 (2000-06-01), Dawson
patent: 6082337 (2000-07-01), Fujimoto et al.
patent: 6089081 (2000-07-01), Cook et al.
patent: 6105556 (2000-08-01), Takaku et al.

Affiliated with

Also associated with

Rating

Fuel system leak detection does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Fuel system leak detection, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fuel system leak detection will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-983090