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speed sensor on efi not hooked up--big deal?

b4opec

New Member
Joined
Jun 28, 2005
Messages
71
Loc.
Sausalito, CA Marin
I converted to efi years ago but to date, still haven't gotten around to putting the speed sensor (off the speedo cable) in. There's a duff's bracket for the shifter in the way; I need to cut it and weld in a U to clear the speed sensor. I can tell that the computer gets a little confused sometimes, especially coming to a stop, the engine idles high for a few seconds before settling down. That's about it though, far as I can tell. Can anyone here tell me if I'm majorly disadvantaging myself by not having the sensor installed?

I'm also wondering if I need to flash the system--reset it--so when I go to drive it around and let the computer 'learn' for a few hours it can do so with the speed sensor installed and sending info to the computer. That brings up another question, when you disconnect the battery, does that effectively reset the computer? Or for that matter is the computer always learning? If you run the computer with one setup then make a change, will it adapt to the change? Or does it need to be reset to start from a base of 0?

I'm curious and I know you have the answers.
 

Socal Tom

Bronco Guru
Joined
Feb 12, 2004
Messages
2,442
Loc.
San Diego, CA
From what I've read, the speed sensor ( VSS) is helpful in manual trans cars with manual trans computers when coasting to a stop.
The ECUs are always learning and adjusting to changes, but if you change out a part, its probably better to disconnect the battery for 10 minutes, other wise it takes about 40 trips before it starts to adjust things.
Tom
 

a67and77

Full Member
Joined
Jan 1, 2003
Messages
589
Loc.
Albuq.
I did my swap about 5 years ago and never hooked up the vss. Never really had a problem but now having idling fluctuations when at a stop light. I'ts supposed to keep from stalling on standard vehicles.
 

casadejohnson

Bronco Alchemist
Joined
Jan 21, 2005
Messages
3,587
My VSS is not hooked up but hanging next to the speedo cable for the exact same reason as yours. I keep telling myself that I need to modify the floor shifter bracket but so far (5 years) I have not gotten to it.
 

Steve83

Bronco Guru
Joined
Jul 16, 2003
Messages
9,124
Loc.
Memphis, TN, USA, Earth, Milky Way
The KAPWR only needs to be removed for 5 min to clear adaptions, and it only takes ~10 miles of varied driving (not cruising steadily) for it to re-adapt. It continually adapts as driving conditions change, & as sensors/actuators age.
 

broncomitch

Bronco Guru
Joined
Jan 17, 2008
Messages
2,384
Loc.
west jordan, utah
not the same. but relevant info.

i was installing a painless harness for a customer, corvette motor and elc valve body tranny. found out,with out the vss every time you push on the brake the motor will die.

i would think that you will be ok with out it.
 
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