Fast Wide Band 02 Concern

[gmturbo]

Fast management question????

I have run into a road block with this problem.

My 87 GN has the FAST/sequential on the car for 4 years now.
The car was dialed in last year with only 5-7% of correction in closed loop. The beginning of this year the car started to run very
rich at idle & on accel. I check for vacuum leaks, changed spark plugs, check fuel pressure (same as before) check fuel pressure
regulator, checked to see if injectors leaking down and all are fine
I checked the program and found the reading for UEGOS (V)
in red and reading .44. From all the feedback I received I felt it pointed to my wide band 02 sensor. I ordered a new one with the
software to re-program the new sensor to the ECU. Started the car up and now the reads are as

UEGO (V) .65

UEGOS (V) .51

UEGOR (V) 4.51 and it is highlighted in red.

The car still runs rich and chugs. Does the reading in red mean there is something wrong with the sensor or not? I changed the car into open loop and it is no different. When I try to lean the car out using the VE tables it stumbles and stalls, when I put it back
it just dumps fuel. I'm stuck and need some sound advice from
fellow FAST users please

Its been 4 weeks trying to sort this out and I have to walk away
from the car after hours of trying to figure it out so I don't drive off a cliff.


Guys I'm looking for help badly.

thanks

 

[bobc455]

Have you checked the other corrections besides O2? Like batt corr %, etc.? Maybe you have low voltage or a bad CTS or something.

On the "big" dashboard, there is a parameter showing total correction- have a look at that and see if you are getting richer because of something else.

If it ran fine in open loop last year, and runs rich now (still in open loop), then the computer might be adding fuel for some other reason.

-Bob Cunningham
bobc@gnttype.org

 

[gmturbo]

Bob,

Thanks for the info, I just came back from the garage
and noticed the connector for the CTS is broken, its just ever
so gently resting on top of the sensor but not making contact.
I will order new one tomorrow, hope this fixes it. I would like to
thank you very much for the direction, people like you keep you make it worth while owning a GN with a FAST system


Conrad

 

[ZBass28]

Originally posted by bobc455
Have you checked the other corrections besides O2? Like batt corr %, etc.? -Bob Cunningham
bobc@gnttype.org

Out of curiosity....what would be a normal/acceptable reading for Batt. corr. %? I think right now I am seeing 0.8% but have no idea what to relate that to.