My PFC O2 control when turned on, has always worked until yesterday.

I was doing AFR tuning with a friends datalogit, and had the air pump disconnected. At the end of the session, we did a READ, and "RE-CALC" which takes the inj fuel correction map and directly applies it to the base fuel map then places "1.000"s in the correction map. Then we wrote the new maps to my PFC. At this point the idle went bad and will not relearn with the O2 control on. I have tried everything to no avail. With it off, the engine idles great.

Maybe the O2 pump needs to be connected when the "write" is done for the PFC to know what is happening. I will try this the next time I use the DATALOGIT.

Has anyone else had this type of problem?

 

Nope. Did that a couple of times yesterday while tuning. O2 and idle are fine, still...

 

I connected the air pump back, set the O2 idle control to on, and did a recalc again. The O2 idle control will not settle down. It fluctuates from 500 to 1200 rpm with too much fuel. No amount of adjustments affects it. Even took off the ISC solenoid and cleaned it.

The recalc fucked something up in the PFC!

 

Hey Chuck, you should prob write something up on the Datalogit mail group about this. There seems to be quite a few people talking about very rough idle lately.

I dont think I'm going to use the recal untill some more info comes available.

Also, months and months and months ago Carson (Spyfish007) had a post in here about how to set up your idle to read from the actual map instead of the PFC just doing it by itself. He turned something down to like 200rpms and the computer just switches over to the map instead of auto tuning the idle. That might help because then you'd be able to tune the idle yourself. I'd look up that thread but I dont have time at the moment.

STEPHEN

 

With the O2 idle control turned off, the idle is fine and the O2 voltages are still low, but the engine runs a little bit richer than if it worked.

 

Chuck,

Is the narrow band O2 sensor any good? Put a fresh one in there and see what happens?

Tony

 

It has a very low mileage stock sensor.

The recalc fucked something up!

 

chuck, iirc, with stock ecu, the airpump dumps air into exh ports, after idle combustion, and o2 output is dead low and not used at idle.

to get o2 control at idle, dump pump air only to the main cat. otherwise mix will be very rich, to allow added pump air outside the chamber, and get good o2 reading?

 

Chuck did you ever figure anything out about this??? You get it to idle correctly???

STEPHEN

 

Nothing has been resolved. Since I am not the owner of the DATALOGIT, I could not directly contact the mailgroup. The owner has been notified of the problem and I belive he has contacted them.

I have the air pump connected as normal, have the O2 control off, and adjusted some of the fuel cells around idle and light load area for leaner running.