| EFI speed sensor repair [message #337182] |
Sat, 22 September 2018 12:34  |
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RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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Senior Member |
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The vehicle speed shown on my EFI EBL Whats Up Display (WUD) was jumping up by 50 to 100% or more. My engine would also randomly stumble.
I disabled deceleration fuel cut-off (DFCO) because I thought maybe the EBL was thinking I was decelerating, but now I think it was tripping the Over-Speed limiting.
A new sensor was $140 (US), so I thought I would take it apart and see if it was repairable. It consists of a magnet and a reed switch which by my testing was switching erratically. I ordered a new reed switch from Digikey for 72 cents (CDN). Using my drill to spin the magnet, it now switches with a clean square wave.
$139.00 saved!
http://www.gmcmhphotos.com/photos/speed-sensor-repair/p65253-speed-sensor-repair.html
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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| Re: EFI speed sensor repair [message #337463 is a reply to message #337182] |
Mon, 01 October 2018 08:35  |
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RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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Senior Member |
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Just an update on my speed sensor repair.
We finally got a chance to really test the repaired VSS. We were going to a wedding at a private venue about 1.5 hours away and secondary roads all the way. I used a Bin with little VSS smothing filter in the way up. The speedometer on the WUD stayed fairly steady, no wide jumps in speed like before. I had loaded another Bin with the higher VSS filter smoothing that Randy V suggested. The speedometer on the WUD display was now much smoother in operation and very steady.
So my $72 cent repair part worked WOO HOO. saved $140.
Also, with many stops signs on the secondary roads, my transmission shifted flawlessly the whole way..
better touch wood now!
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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