Fitech EFI Rpm Noise Solved

Thanks,
The Fitech setup works well but it is not plug and play (nor is any other FI setup) The basic settings will get you up and running but you are going to have to do some of the tuning yourself. Also you are going to have to shield some of the wiring to avoid the RPM noise error. There is a lot of help here on this forum. PM me if I can help.

I had a similar RPM noise issue with a Mega Squirt install, massive interference would not allow the motor to start / run.
the MS 3 Pro harness that attached to my distributor leads, I am using a locked lean burn distributor, had foil grounded insulation inside of the wire bundle, I found an EMI / RF article that stated there are times when grounded fol is not enough, and the fix is to add woven wire shielding over the foil.
and that was my fix for the RF interference. For the EMI side I moved the main engine block ground from the cylinder head to one of the starter mounting studs and all was good.
below is a link with additional info

After Market ECU's and EMI interference - Slant Six Forum

also the woven wire sheathing is available in wire size diameters, 1/8, 1/4, 3/8 ,,, for not much money, I think I paid $9.50 shipped for 10 feet of 1/4 inch diameter braided wire sheathing. Got mine from Electriduct e bay store
also, whether it is foil or woven wire, only ground one end of the shield.