Any ideas, guys? It's a Nordskog digital tachometer, and I wired everything up as per instructions, and it's accurate...until about 4000 RPM and higher. It will just drop, to like 2600 RPM. Engine runs fine, just the display is off on the tach, and only after 4000 RPMs. I KNOW it can't be a bad ground, because I ran a 10g ground wire exclusively from the chassis to my gauges. Any other ideas?

Oh, and just so you guys know, I'm running a Delteq ignition system on my 1993 Camaro (and I've removed the tach filter, found exclusively in the 93 F-bodies- this was necessary for the OE tach to read accurately after the ignition conversion)...

 

Figured out the tach problem, thanks to the help of J.C. @ Delteq. He called Nordskog for me, and they told him their gauges were setup only to run on a 12v signal, and with the Delteq ignition system, the signal was only 5v. J.C. gave me step-by-step instructions on what I had to do. Basically, I had to piggyback a 1/4-watt 10k-ohm resistor onto another 1/4-watt 10k-ohm resistor, which was already soldered to the circuitboard. I disassembled the gauge, soldered the resistor where J.C. told me to, reassembled it, and it reads correctly now!!

 

sweet! glad you got it fixed.