hey guys does anyone know anything about a tach filter?? My current tach reads for maybe a minute then drops to zero. It was working when i got the car from PO. Tach wire is tapped properly. power and gnd is good. I opened the tach to see if any wires on the board were sketchy. I have electronics experience so i would be able to fix it but they were all solid. The board inside the tach was extremely hot, car was only running 5 minutes. I know this can happen with circuits but not sure if thats normal. Anyway after re reading the tach instructions i noticed a note that said if you have an after market hei dizzy you may need a tach filter. cant find much info on a tach filter though. Im sure that the tach went nuts after i changed the stock dizzy to an HEI ACCEL with vac. So my quetsion is really is it a tach filter or did the tach just take a poop.
Thanks in advance.

Sunpro Supertach II. !982 Camaro V8 Carbed.

 

That capacitor isn't in there because the system uses points:



That one is to kill the biggest spikes from the coil primary (mostly for RF) and there should be a similar dual R/C network downstream to reduce/split the signal from the coil to the tach electronics.

The Accel system may be similar to the MSD, in which case it would need to use an INLINE FILTER.

 

thanks for the response Vader. That cap definitely isnt there. I will assume that the tach filter is necessary based on ur explanation. Ill give it a try.