TACHOMETER ISSUE

[Rick Allen]

Just got my '83 out of storage after 18 mounts, it started right up after a little gas down the carb but I noticed the tachometer is only moving very little, idle at 400 rpm, normal hi-way driving 7-800 rpms, it was working fine when it was parked.

Anyone have any suggestions as to what may cause a tach in these cars to act like this and how to correct it?

I should add, everything is factory, no aftermarket ignition or any other parts were changed!

Edited June 3 by Rick Allen

[mfg]

21 hours ago, Rick Allen said:

Just got my '83 out of storage after 18 mounts, it started right up after a little gas down the carb but I noticed the tachometer is only moving very little, idle at 400 rpm, normal hi-way driving 7-800 rpms, it was working fine when it was parked.

Anyone have any suggestions as to what may cause a tach in these cars to act like this and how to correct it?

I should add, everything is factory, no aftermarket ignition or any other parts were changed!

Don’t know the answer, but I can say that the tach in my ‘83 also acts strangely… In cool weather it seems to work perfectly….however during the summer it always reads low, rarely indicating over 2000 RPM no matter what the road speed!

[ronmanfredi]

The tach signal is picked up at the HEI distributor cap.  Pull the wire off the distributor cap (or all 2-3 of them), clean the connections and reinstall.  Also, check the ground connection at the back of the gauge (white wire).

[Rick Allen]

14 hours ago, ronmanfredi said:

The tach signal is picked up at the HEI distributor cap.  Pull the wire off the distributor cap (or all 2-3 of them), clean the connections and reinstall.  Also, check the ground connection at the back of the gauge (white wire).

Thank you, I'll try that,,,