Fooled O2 Sensor?

[Syclone#892]

So here is my problem
I am trying to get my sy up and running and its just being a big pain. I had it running many years ago with the current fuel system till the trans went out.
Since then I have rebuilt the trans, had the engine gone through and made sure everything was good to go with it, switched to a t-72 with 3.5 downpipe with 2 o2 bungs, front mount ic and a couple other items.
Well I am having a problem with tuning, wb and truck comp says its running lean, to me it seems like the truck is running rich. We have added tons of fuel in the chip with no help. It will not run with my old chip even though not "much" has changed tune wise.

I am just stumped and I feel like I am over thinking this but here is what I have.
Thought maybe bad o2, installed new ngk, no change. When the truck is running it just has that running rich smell to it :tdown:
Not sure if this would be an exact test, plus I didn't do it for very long but I unplugged the stock o2 and that made the wb show around 10-11 at idle and when I would rev it up in park it would go to maybe 13 at the highest.
So right now I am thinking that somehow the stock o2 is reading wrong but can't think of how or why. with the o2 plugged in the wb will read 15 ish at idle and will bounce between 15-20 when revved up.
I did check the plugs and they have a dark color to them not the usual white when lean look.

I am getting some knock retard which I completely believe is false as my torque converter is making some noise, I haven't been able to change it out yet since my boss stole my trans jack. I also recently found another rattle noise from the internal wastegate, if I am remembering from last yr I have it set a little loose so it won't build much boost but I guess I need to check and tighten that a little bit more.

Time to work on the truck is pretty limited right now but in the coming weeks I plan to really get back to working on it so I can finally have some fun with this money pit.

One more thing for me to consider is the possibility that it could have a misfire, problem is to me it doesn't really act like it has a miss and all wearable parts are new and the dist is the same reman one I used yrs ago.
I will look harder at the ignition soon also and see if I can find a problem with it. I have ur6 plugs in it gapped at .30 wonder if I should throw some ur5's in just to see if it will change anything. I have a set for the so gt laying around anyway. Hmm things to think about.

So hopefully someone has a couple ideas I can try and I can get this thing worked out fiinally.

Thanks for the help!!!

 

[turbodig]

Re: Fooled O2 Sensor?

Generally, your senses and or instincts are correct.

Don't automatically assume that your WB controller is good.... just changing sensors will repeat the problem.
Interestingly enough, my DIY-WB is exhibiting the same symptoms - reads lean even though I know it's way rich.

Find another local with a WB controller you can borrow for a while. Alternatively, take yours out, and stick the sensor in the tailpipe of another car with a factory calibration and a narrowband sensor. Once it's warmed up (both the vehicle and the sensor), it should read right around 14.5-14.7. If it doesn't, you'll know you have a bad controller.

Also, you can "check" a wide-band with a propane torch- turn the gas on (don't light it) and put the warmed up sensor in the gas stream (you'll probably need a pliers to hold it). It should read really rich, down near the bottom of the scale.

 

[Syclone#892]

Re: Fooled O2 Sensor?

Well I think I got the truck figured out tonight.
I have not changed the wb sensor just the factory o2 with an ngk brand sensor.

Interestingly I did do the torch this last weekend and to me the sensor was not reading right as it was staying around 20.

Well anyway after reading about how a miss or too rich of a situation could fool the sensor into thinking it was lean(because it wouldn't be able to read the small droplets of gas going by)
I began to wonder if my coil was bad.
I was going to convert to ls1 coils and have all the pieces to do it but I decided to change the serp belt setup and now the crank trigger would not work anymore. So I figured I would just get the truck running with the dist and once the truck was doing decent then I would brainstorm how to make the ls1 coils work.
Well lost my old coil and coil wire so I found on old coil and wire laying around and just kinda figured if the truck ran that they were okay parts:banghead:
I have a nice msd coil 8252 somewhere but can't find it, so my dad lent me a msd coil and crane ignition box that he has for his truck.
I threw that on temporarly, set fuel pressure down to 50, threw an old chip in it and now its running rich like its suppose to and the sensors are showing it.
Kinda wierd I am happy to see that its running rich but I feel like I am back to the point I was yrs ago in the tune which is far better than this mystery I was having.

Now I have to put lots of things back together on the truck and find all the false knock this thing has

Thanks for the input Dig:tup: