mvvette97

iTrader: (18)

I have my 97 vette tuned and now I noticed that when I was running a log that I didn't go to open loop at full throttle like it's supposed to. what causes this to do that?

foff667

iTrader: (2)

If your PE delays are setup so that you won't go into open loop this could happen.

-Bill

mvvette97

iTrader: (18)

Hmm, maybe that's it. Do ya know what tables to look at to see if that is the problem? I don't have HP but EFI so I'm guessing it is completely differant

Jason Haines @ LPE

On the 1997-2004 Corvette PCMs (and the 1998-2002 Camaro/Firebird and most other similar PCM data streams), GM doesn't show the vehicle going out of closed loop when you are at WOT even though you are really no longer in closed loop. The closed loop term shown in the diagnostic data stream refers to being in closed loop enable mode due to engine coolant temperature and start-up time. So what I am trying to say (maybe not very clearly) is that you can be (actually will be) in Power Enrichment and it will still show closed loop mode in the data stream. That is normal (this is not the case in all GM data streams, many of the V6 data streams I have looked at actually show you that you aren't in closed loop when you go into PE as do the newer Corvettes, 2005+).

To see if you are in PE (no longer in closed loop) at WOT, you need to look at the fuel trim enabled variable or you can look at the target air fuel ratio or the PE (Power Enrichment) enabled variable.

You can also usually see the change in your O2 sensor voltages and/or your wide band AFR meter.