Lambda sensor and air fuel gauge

[mpk490p]

ok i have a air fuel gauge i want to hook up to a lambda sensor, my car is a 1st gen so no sensor as stock, i brought a universal 4 wire one 2white 1blk 1grey, the gauge wiring diagram says hook the single white wire to the ecu wire, the instructions for the lambda sesnor says 2 white 12v+ grey 12- blk signal, but not joy with the black, i get some kind of signal from the grey but the gauge just reads round to lean then back to full rich,
i\'m hoping its not the gauge could it be the sensor? it was new, is there anyway to test them?
thanks
Mark

[Prof]

The pinout for that 4 wire sensor:
 
Black - signal +ve
Grey -  signal -ve
 
White pair - heater - connect to 12v via fused switched source
 
To get anything sensible out of the sensor signals - you need a sensitive input meter - the gauge you\'ve got will probably do it - you need to ground the grey wire, and feed the black wire into the input of the gauge.
 
Don\'t expect steady results on the gauge - the sensor is a narrow band one and so will just swing rapidy from rich to lean and back - if you want to see proper A/F ratio\'s - you need to get a wideband controller - such as the innovate LC-1 - you can still use the gauge you brought and feed it from a 0-1V analog output on the LC-1 - the manual shows how to set this up.

[mpk490p]

thanks Dave i will take another look tomorrow, but it was just swinging from full rich to full lead on tick over!?!
looks like more pennies! i wanted to go wideband but was hoping this would be ok just to get my 51IDA on the car before i got it on the rolling road!
the gauge i have just has 1 wire input though?

[grinder]

im sure that mine used to bounce around a lot - but on WOT it always showed rich

thing with mine - i used to use it like a rev counter ... with slight throttle variation i could get it to drop a few points on the scale

not sure if it actually did anything - but it made the boring motorway journeys more interesting !

[mpk490p]

its just so i can get a \'base\' reading from my current carb and match it with the new one untill i get it to a tuner will have another play today
Mark

[mpk490p]

thanks guys solved the problem
it was the wally with the screwdriver!
i had the 2 white wires connected to 12v+
grey as signal and blk as earth (which i thought was wrong but just didn\'t make sense, blk is always earth!)
all sorted now it sits just in rich on tick over and does jump up a down a bit, but its a good gauge for me to get the 51IDA set up to

Mark

[mpk490p]

White pair - heater - connect to 12v via fused switched source
 

Dave does the heater wire need to be on all the time the igniton is on?
any idea on what size fuse to use?

thanks
Mark