500EFI tach bounce
 

Has anyone experienced gaffrig or livorsi electronic tach bounce after changing wires over to MSD helicoil solid core or any other solid core wires? It the only change I made over the winter and I now get tach bounce or flutter over approx 3000 RPM. I had already grounded the distriutors to the engines in the past due to minor tach fluctuations which solved that problem. This problem is common to both sides as the flutter is almost in unison with each respective side. My guess is RFI but I threw the old wires out.

Re: 500EFI tach bounce
 

stupid question but did you check the cond of the cap and rotor ??? carbon or corrosion build up will give you a "tach bounce"

just because it looked good before putting up doesnt mean it still is

Re: 500EFI tach bounce
 

I believe your guess on RFI is correct. Are you sure your MSD wires are solid core? I thought all MSD wires were compatiable with all currents electronics, and they would be of the spirial wound type? What type of construction were your old wires? I changed out the stock blue wires on my HP500EFI to the 8.5MM MSD spirial wound wires with no problem.

Larry

62 Bel-Air 409 ( for sale )

260 Eagle XP HP500EFI

2002 Corvette M-6 Coupe

Re: 500EFI tach bounce
 

Cap and rotors are new and the wires are spiral wound heli coil 8.5 MM for marine aplication from MSD, probably identical to what you have on yours. The spiral wound element is a non carbon conductor that supposedly gives the best possible RFI reduction and still have a wire conductor. The cap and rotor are merc factory pieces. I cut apart the merc factory wires at the time of replacement and determined that thy were carbon wires. Plugs are gapped per merc specs and wires are loomed and routed exactly the way they were previously.

Re: 500EFI tach bounce
 

Has a anyone had any luck with using a noise filter in a tach circuit?