Water Temp Sensor?

[TurboFortysx]

Over the past couple weeks my gas mileage went from good to horrible. I get 200 miles out of a full tank! I changed my plugs, new O2 sensor thinking that it might be the cause. Wrong. I went to the dyno today to tune thinking it is a bad tune. I kept leaning the fuel out and nothing happened. I am running 10:1 idle and cruising. Full throttle is fine but when the O2 is in loop nothing changes it. I am thinking it is a faulty water temperature sensor but not sure which sensor the CA uses. Any ideas on the part number or the cause? Thanks!

[The_Chosen_One]

http://www.partsamerica.com/Pr...ensor

[capowered240]

engine temp sensor probably has gone bad. It's located right next to the water temp sensor.

http://www.partsamerica.com/Pr...85029

[TurboFortysx]

Well nothing changed still rich as crap. Any other ideas?

[float_6969]

Have you pulled the codes from the ECU? do you have an AFR meter? Are you sure that you don't have a bad connection on the signal wiring going to the ECU for the O2 sensor?

[ca18datsun510]

sticky injector?

[TurboFortysx]

I was thinking a sticky injector but not sure yet. I am using a wideband meter on a buddies dyno. The car runs great on closed loop under full throttle. On open loop I can lean it out to almost nothing and the a/f does not change. Is there a cold start relay?

I also used a new O2 sensor that was listed on the crossover parts list. I did have to extend my O2 wires on the harness but they are all soldered and heat shrink wrapped. I hope there is no interference, but it was running rich before I did the sensor.