Interpretation ID: nht74-1.26
DATE: 05/23/74
FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA
TO: Mazda; Toyo Kogyo U.S.A. Representative
TITLE: FMVSS INTERPRETATION
TEXT: This is in response to your letter of May 9, 1974, requesting an interpretation of the test procedure specified in Standard No. 301 (Docket No. 73-20; Notice 2) concerning the operation of the vehicle's fuel pump during testing.
Paragraph S7.1.3 of the standard requires that electrically driven fuel pumps be in operation during the barrier crash tests if they normally operate with the activation of the vehicle's electrical system. If the pump is incapable of functioning with the independent activation of the electrical system and requires the operation of the vehicle's engine, then the pump should not be running during the barrier crash tests.
Based upon the description you provide in your letter, it appears that you should conduct your barrier crash testing without operating the fuel pump.
Yours truly,
ATTACH.
May 9, 1974
Richard B. Dyson -- Assistant Chief Counsel, U. S. Department of Transportation, National Highway Traffic Safety Administration
Dear Mr. Dyson:
Re: MVSS 301 Fuel System Integrity
In section 7.1.3 of Docket 73-20; Notice 2, we can find, "If the vehicle has an electrically driven fuel pump, that normally runs when the vehicles electrical system is activated, it is operating at the time of a barrier crash."
The underline was added to the Docket 73-20; Notice 1.
Although we feel NHTSA has granted our attached comments on February 8, 1974, hereby we confirm it again.
Our electrical fuel pump works only when the engine runs, and usually does not work when the ignition is in "on" position except that the engine works. In other words, our electrical fuel pump is connected to the engine and there's no relation directly from our electrical system in "on" position. Nevertheless, we will find that the vehicle's electrical system without fuel pump is activated, when the ignition is in "on" position and the engine is not in "running."
Our question is as follows: In the above system, we believe we may test the barrier crash without operating the electrical fuel pump. If its not so, we have to test it with another special connection between battery and fuel pump, "only on test."
Your opinion will be highly appreciated.
Always warmest,
Goro Utsanomiya -- Branch Manager, TOYO KOGYO U.S.A. REPRESENTATIVE OFFICE
cc: Mr. Williams; Mr. Makino
February 8, 1974
James B. Gregory -- Administrator, National Highway Traffic Safety Administration
Dear Dr. Gregory:
Although the comment closing date is already over, we would like to submit the following comment, because we have a new problem by further review.
It would be appreciated if you consider this comment.
Sincerely yours,
Gorou Utsunomiya -- Branch Manager,
TOYO KOGYO U.S.A. REPRESENTATIVE OFFICE
cc: R. N. Williams
enc.
DOCKET 73-20, NOTICE NO. 1
COMMENTS OF TOYO KOGYO CO., LTD. ON NOTICE OF PROPOSED RULEMAKING FUEL SYSTEM INTEGRITY PASSENGER CARS, MULTIPURPOSE PASSENGER VEHICLES TRUCKS AND BUSES (OF 10,000 GVWR OR LESS)
Comment
"S.7.1.4 - If the vehicle has an electrically driven fuel pump, it is operating at the time of a barrier crash test" should read as, "S.7.1.4 Ignition switch is at "On" position at the time of barrier crash tests."
Discussion
As you know, electrically driven fuel pumps are used on many cars. As far as we assume, this S 7.1.4 is established so as to minimize possibility of fire at the crash accident because electrical pump will keep working as long as ignition switch is at "On" position.
However, if we develop a system where the electrical fuel pump stops at the moment of impact in spite of ignition switch being in "On" position, this possibility will no longer exist.
As long as S 7.1.4 exists, we have to make the pump work by other means, such as direct connection between battery and pump, when we conduct a compliance test, and this S 7.1.4 will close the way of possibly developing a new safety device. We think that this situation is far apart from the actual one and this test is impractical.
Judging from the fact that there is no requirement, "Mechanical fuel pump is operating", we think S 7.1.4 can be changed. Needless to say, we recognize that we should minimize the possibility of a fire with electrical pumps. We would suggest S 7.1.4 should read, "Ignition switch is at "On" position.