Help! Tach Signal Disappears - Holley HP EFI

[71RS/SS396]

If you don't have the billet 24X reluctor wheel that's where I would look. The 2 piece ones GM and the aftermarket are using are prone to problems, I've seen excessive runout and also seen the welds let go.

[ROKN69]

Hi Guys,

We figured out the case of the disappearing Crank Signal issue. The shop had installed a driveshaft speed sensor, and I had requested they disconnect the sensor as part of the troubleshooting process. Basically, what was the last thing that changed? Undo that!

They disconnected the driveshaft speed sensor at the sensor (about 6 weeks or so ago), but not at the ECU. There was a wire that had gotten pinched in the transmission tunnel that was somehow causing issues with the ECU. They thought to disconnect from the ECU and the problem has completely cleared up.

Thank you all for your ideas and suggestions! Much appreciated.

[ROKN69]

Originally Posted by 71RS/SS396

If you don't have the billet 24X reluctor wheel that's where I would look. The 2 piece ones GM and the aftermarket are using are prone to problems, I've seen excessive runout and also seen the welds let go.

Thank you, Tim. We plan on installing a billet 24x reluctor wheel this winter.