a/f ratio gauge

[sleepy240sx]

ok....first of all i have already searched and i already know that a/f ratio gauges are a "useless light show" if its not wideband....so please dont reply by telling me these things...
anywho....
i have an a/f ratio gauge and i have been trying to get it to work but it doesnt.
i have a red top sr20. i tried connecting it to the white wire coming out of the o2 sensor and it doesnt work....then i tried the black and red but it still doesnt work....

my next best guess is that i need a new o2 sensor. i also heard that you cannot get a a/f ratio gauge to work on the older sr's....but i dont know how much of that is true...

any ideas???
thanks.

[cotbu]

i also heard that you cannot get a a/f ratio gauge to work on the older sr's....but i dont know how much of that is true...
Never heard that....

Anyway your electronics that do not have there own sensor, should be wire at the ecu. Yes I'm sure that there are some sensors that you would just tap, but in this case 02 is not one of them. Fix your wiring install your gauge.

[5t341tH]

tap into the o2 wire at the ecu.

[sleepy240sx]

which one is the o2 wire???

thanks for the help

[jilo]

look man you sateted it yourself in your first sentance, its a useles light show. it isnt gonna tell you shit so whats the point for having it hooked to a stock o2 sensor? it only reads on/off basically so theres really no point in doing it. newer cars have lambda sensors and can read a gradient of a/f, where the o2 sensor in a redtop cant. this might help, it might not. depends if you read wiring.

http://www.sr510.com/tech/sr20det_eccs.gif


SR20DET wiring ECU pins and description of wire colors

1 - Coil Pack 1 Output (Via power transistor Unit) - Red White
2 - Coil Pack 2 Output (Via power transistor Unit) - Red Yellow
3 - Tachometer signal output - Yellow Red
4 - ECCS Relay - Red Black
5 - Ignition Pulse Monitor (For Trip Comp ?)
6 - Ignition Signal Ground - Black
7 - RX data (Signal from Nissan Consult hand terminal) - Green Black
8 - Coil Pack 3 Output (Via power transistor Unit) - Red White
9 - Coil Pack 4 Output (Via power transistor Unit) - Red White
10 -
11 -
12 - A/T signal DT3 (autotrans gear select ?)
13 - Ignition Signal Ground - Black
14 - CLK clock (timing signal) - Green White
15 - TX data (signal to Nissan Consult hand terminal) - Green
16 - MAFS signal input ( Mass Air Flow Sensor ) - White
17 - MAFS ground - Black
18 - Water Temp Sensor input - Blue Brown
19 - Oxyen Sensor input (O2) - White
20 - TPS input (throttle postion sensor) - White
21 - Sensor ground - Black
22 - CAS 180deg signal (Crank angle sensor) - White
23 - CHK check (check start) ? - Green Red
24 - Monitor check Lamp (red) (fault code lamp output)
25 - Exhaust over temp warning lamp output - Orange
26 - Exhaust temp sensor inout (Behind the Cat) - Blue Yellow
27 - Detonation sensorinput (knock sensor) - White
28 - TPS for A/T (kick down switch)
29 - Sensor ground - Black
30 - CAS 180deg signal (crank angle sensor) - White
31 - CAS 1deg signal (crank angle sensor) - Black
32 - Speed sensor input - Yellow Green
33 -
34 - Start signal (from ignition switch) - Orange
35 - A/T neutral switch input - Green Orange
36 - IGN (ignition ON, from ignition switch) - Black Red
37 - TPS power output (power to throttle position sensor) - Light Green Red
38 - ECCS power - Black White
39 - ECCS ground - Black
40 - CAS 1 deg signal (crank angle sensor) - Red Black
41 - A/C on input (Air Con ON from A/C panel) - Blue Green
42 - A/T signal DT1 (auto (http://www.240sxforums.com/forums/showthread.php?t=433#) trans gear select ?)
43 - Power steering switch (speed proportional control output) - Purple White
44 - A/T signal DT1 (auto trans gear select ?)
45 - Ambient air tamp sensor input - Blue White
46 - ECCS backup power - Red
47 - ECCS power - Black White
48 - ECCS ground - Black
101 - Injector No. 1 drive output - White Black
102 - EAI control solenoid (http://www.240sxforums.com/forums/showthread.php?t=433#) output (egr valve control ?) - Orange Black
103 - Injector No.3 drive output - Green Black
104 - Fuel pump relay output - Black Purple
105 - Fuel pressure control module - Red White
106 - A/C on output (Air conditioner on relay signal) - Green Black
107 - Injector ground - Black
108 - Injector ground - Black
109 - Reverse electrical flow return circuit (alternator fail input) - Red
110 - Injector No. 2 drive output - Yellow Black
111 - Turbo boost (http://www.240sxforums.com/forums/showthread.php?t=433#) pressure control solenoid (over boost cut ?) - Orange Black
112 - Injector No. 4 drive output - Blue Black
113 - AAC valve control (Auxiliary Air Control, Idle speed control) - Light Blue
114 -
115 -
116 - Injector ground - Black