is 80psi the maximum on the gauge?
if so the sender wire may be earthing out... try wiggling the wire around and see what it does
try another 2nd hand sender unit (should be el cheapo for one)
if still no go... get an aftermarket one lol
those light show a/f gauges can lie...
try doing the vf check from your diagnostic box
plug a couple of wires into VF and E1 of the diag box
attach the VF wire to the red of the multimeter set to dc volts and E1 to the black prong of the multimeter
get someone to go with you so it's easier....
5 volts = adding lots of fuel from base maps
3.75 volts = adding little bit of fuel from base maps
2.5 volts = no change from base maps
1.75 volts = reducing some fuel from base maps
0 volts = reducing lots of fuel from base maps
The Vf will go to 0 volts when decelerating, and when accelerating and going into open loop (richer than 14.7 A/F). Ignore the Vf output at idle.
what voltages does yours put out when you go wot or just accelerating etc
GL
