Problem with Vintage Tachometer on 302

[MaxL]

Hi,

I got my kit with a set of FFR vintage gauges last October. After finishing my build and getting it to run I noticed that the tach needle jumps quite a bit. The higher the rpms the more it jumps. At idle it's almost steady, may be some movement if at all. The tach is connected to ECU tach output, but I also tried to connect it directly to the negative post on the coil with the bypass wire - same result. What do you folks think, is it a defective tachometer or do I need to install some sort of signal filter? Btw, I'm running 302 with Edelbrock ProFlow ECU that has a bluetooth and the app shows revs clearly with no issues.

[wallace18]

Hi,

I got my kit with a set of FFR vintage gauges last October. After finishing my build and getting it to run I noticed that the tach needle jumps quite a bit. The higher the rpms the more it jumps. At idle it's almost steady, may be some movement if at all. The tach is connected to ECU tach output, but I also tried to connect it directly to the negative post on the coil with the bypass wire - same result. What do you folks think, is it a defective tachometer or do I need to install some sort of signal filter? Btw, I'm running 302 with Edelbrock ProFlow ECU that has a bluetooth and the app shows revs clearly with no issues.

Call Speed hut. they will send you the correct filter. I had same problem with a MK4 I built for a customer in Miami.

[AC Bill]

I'm not sure about the Speedhut gauges, but my Classic Instrument tach instructions said, to be sure and use a dedicated ground for it. If you grounded it to a location that other gauges, or electronics are being shared with, that might be an issue.

[MaxL]

Thanks for the advises! I will try to call Speedhut next week and meanwhile might try with the grounds. All my gauges are on the same ground wire, which is what the instructions said.