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Old 11-10-2009, 07:30 PM   #80 (permalink)
EcoModding Lurker
Join Date: Dec 2008
Location: lone star state
Posts: 55
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look what your doing.?
if you are powering up and power down electronics , (full power) all the time
this puts huge surge stresses on it. ( a switch happens in almost zero rise time )
and is brutal to electronics equipment. (most ECU'S can take it but....)

best is to cut the signal out of a CMP.
this sensor is just a hall effect sensor and please do not cuts its power feed , just its output line.

Just like keying on and off 1000 times, its bad, and not just bad for the key switch.

as i sad cutting the injectors , cools the cat and makes smog.
safer is cutting the CMP but is still dirty smog wise.
using the gas pedal keeps the cat hot and saves gas and is Green.

Most ECUs are programmed to do that so ,cruising , the CAT is really hot,
most ECU'S feed it a tiny bit of gas, to keep it Lit OFF. (required by law) at FUEL cut.
and is a Green function. (fuel cut= pull foot off throttle pedal)

Its also illegal to defeat this function , in case you didn't know. (not that i care , just completeness for others that do)

killing power to the injectors will only hurt environment (after restart and during the delayed warm up of the cat) not hurt the car.

killing power to in Ignition modules over and over is , iMHO , NOT too good.
This is also illegal in most states and risks , steering lock up , if done with the key.
Surging the Ignition modules ( price them , price those nice cheap COPs)
is not too good, either, IMHO $900+ at some dealers.

Insites, ( hacking and Insite. wow, i wont go there.)

if you have a new car, using a real live obd2 scan tool , look at the advanced data stream and see the injector PW parameter, with foot off gas.
very very tiny fuel. way less than IDLE ,rate !!!!

most MPG gauges are not accurate on this low end , because they cheat.
they take MAF READINGS and do the math in reverse (14.7:1 ) to arrive at fuel usage. (air , temperature , one can do that ) but
14.7:1 is wrong for fuel cut, dead wrong. so the gauge just overanges.

not all but many. are wrong at cut fuel .

keep that in mind , when looking. and MPG guages.

the only accurate way to get MPG is with GPS for speed
and real Injector PW. (live)
then get the Injector tables and subtract the dead time form measured PW and get actual Fuel flow , based on the actual vehicle fuel pressure.
the mfg of injectors says" at this zone , flow is nonlinear"

Few attempt to do this test accurately.

It only works out accurate at cruise and the fuel cut mode is very inaccurate.
just read up on that subject at the injector mfg sites.

that is my knowledge on ECU'S ( I have a mega-squirt on my car and i had to program all these feature in to it the hard way. so been there done that)

hope this helps. clear up fuel cut , or at least open some doors.

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