I am trying to tune my 1967 ford 289 air fuel ratio using the zeitronix Zt-3 meter. When I attach the meter to my laptop I get a constant full lean reading of 21!!! Meter is attached according to instructions, black wire is grounded, red goes to switched 12 volts, air fuel sensor hung is located about 1 foot from header, all other connections are plug types which only fit one way. The problem may be that I had to splice the air fuel sensor cable because I melted it on hot exhaust pipe. I am sure the splice was done correctly and it was soldered. I called Zeitronix and they say i need a new cable but before I drop $100 for cable I would like to be sure. Is there any way I can test the individual components of my Zt-3 or does anyone have any ideas on what could be causing a full lean reading on my laptop? I am in CT. Thank you for any responses.
Bill
Bill