Running rich, bad o2 sensor?

[Mysterio]

My car has been running very rich even with the fuel pressure turned down lower than stock.

I decided to og out and try things and checked the o2 sensor. The car was still decently warm when I started it up and I checked voltage comming from the o2 sensor and was reading .25-.50 so I went out and had a cigarette and came back to allow the car to heat up.

After the car was heated up, at idle I was only reading .05 volts comming from the o2 sensor. Does this mean it's shot? I gave it some gas couldn't get full throttle but under any kind of acceleration it didn't move from the .05 volts.

I'm getting code 51 which on an 87 shelby charger means 85-88 lean more than 12 min.

The car has a 255 walbro pump and 33 lbs injectors. So I'm guessing that the o2 sensor isn't reading properly, LM is thinking i'm running lean and the injectors are spraying more than they should, which they already support more than I need by far.

Is this logic behind that correct?

I removed the LM and i'm leaving it out for a bit to try and reset it and see if it was just a previous code from the previous owner since he had switched to a 4 wire from the 1 wire and never reset it.


Also does anyone have a close up picture of where the wire that connects to the o2 sensor comes from? So I can make sure i'm wiring my o2 sensor into the correct wire to the LM. I have wiring diagrams but its like reading chinese and I can't find the o2 sensor in em.

[Stevien1]

First off- if this is a stock TI LM, your 33pph injectors are too big (you should be running 27pph unless you have a AFPR). Second- recheck all the wiring related to the O2 sensor, it could be causing your problems.

For pinouts, look at MiniMopar's site.....

http://minimopar.knizefamily.net/ecu/lm-1987-t1.html

Looks like the O2 signal wire is pin 18 in the blue connector at the LM.

[zin]

+1 for what Stevien said. But, I think you are on the right track, the 02 signal should be swinging between approx. 0 and 1 Volt, and should change as engine conditions change, ie idle vs revving/accelerating, if you get no change, and it's wired correctly, I'd say the sensor is dead. My .02.

Mike

[Mysterio]

Ok, where can one buy a mopar performance 4 wire o2 sensor from?

[Turbo_Rampage]

Ok, where can one buy a mopar performance 4 wire o2 sensor from?

Either the Dodge dealer or one of our Venders. If you buy one from the DD be prepared to spend alot of money for it. On my cars all i run is NTK brand O2 sensors, and i have never had no problems with them (the original ones on my TM's were NTK right from new) If you go to Napa you can pick up an NTK 02 sensor for like $50 (i paid $70 for a 4 wire 02 here in Canada)

Hope this helps

[Mysterio]

Either the Dodge dealer or one of our Venders. If you buy one from the DD be prepared to spend alot of money for it. On my cars all i run is NTK brand O2 sensors, and i have never had no problems with them (the original ones on my TM's were NTK right from new) If you go to Napa you can pick up an NTK 02 sensor for like $50 (i paid $70 for a 4 wire 02 here in Canada)

Hope this helps

Awesome thanks. I looked on the vendor sites and it was $85 for a mopar 4 wire, seemed kinda expensive. $50 sounds better.