FAST WB02 off by 2 points?? Show's lean, car is FAT

[J.Bouvier]

We ran our car today on a local superflow chassis dyno, which has built in wide band 02 sensors, so we ran the FAST 02 sensor on the driver side collector and the Super Flow 02 sensor in the passenger side collector. The on all the data logs the FAST showed in the 13:1 to 14:1 range and the SuperFlow ran from 9:1 to 14:1. The car was making lots on black smoke when the SuperFlow side anything in the 9's and 10's. The SuperFlow unit is known to be correct. At higher boost levels we were looking for a/f in the low 11's so the system is try to add the maximum correction factor of 15 %.
So here is my question is there a problem with the WB 02 sensor or the main unit itself? Or possibily with the wiring?


Here is some info on the car:
326 small block ford, FAST B2B system, Procharger F-1r system, TFS high ports, Vortech Igloo, 85lbs injectors.

Any help asap would be greatly appreciated!!!!!!!!!!

 

[Chuck Leeper]

Smokin??

Last Ford I saw do that was due to the intake charge being blown across the manifold into the dr side cylinders and those cyls going so lean they burned gaskets and pistons and torched the head.
The partial cure was to go to a sequential system w/ indiv. cyl tuning.. Ended up running that side much fatter than the other.
Ultimate cure was to move the I/C under the dash, use a 4bbl intake and turn the T/B around backwards...
HTH,

 

[bruce]

Originally posted by J.Bouvier

So here is my question is there a problem with the WB 02 sensor or the main unit itself? Or possibily with the wiring?

I would have switched equipment from side to side.
Might be the engine.

I'd suggest you put a second bung by the one the ecm uses, so in the future you could run them at the same time. I wound up adding a few extras just for situations like that.

 

[JeffB]

have you changed any of your wiring lately? even the routing? we had a FAST WB go nuts when its harness was too close to the factory mustang fan (aka the amp-hungry-sob)... moving the harness elsewhere put it right back in line with the horriba WB on the dyno...

 

[J.Bouvier]

Thanks for the reply guys, the car is still on the dyno so i'll try switching the sensors around to see what happens. If anyone relse anyone else have any idea's I'd really appreciate it!

 

[TTA89]

I heard of another Mustang guy doing dyno tuning this weekend that showed 1 point off.

Heh, how do you tell which is correct?

 

[Rickerbucks]

I have no experience in this but when I first started my car I was running REAL lean. I fattened it up a LOT in the VE tables and though the AFR on the WB worked something was still not right as the car was burning black.

Eventually I found that one of the injectors was not working causing the WB to read a lot of air and thus lean.

 

[Spence]

Joel,
I had this problem for almost 2 years, even tried new sensors with the same results, it actually showed Rich in the datalog, but kept melting the head. It turned out to be a bad ground. For the heck of it, I installed a big fat ground from the motor to the chassis, then back to the battery as another ground source, and bam, the wide band started reading correctly and the car hasnt melted since, even with a leaner tune up......was a strange problem.

 

[J.Bouvier]

Thanks for the reply Spence! I had remembered reading that on your site so I added an extra ground right off the collector by the O2 sensor to the chassis and then back to the battery and on change. We talked to Tony at FAST and Mike Murillo, both side the sensor is used up. So we'll be ordering a new one from Mike asap. How's the new combination coming along??