Swap Startup: Stumbling

[cebra]

They were supposed to tune it as a manual but honestly they are not doing a very good job of making me feel comfortable about the tune as they didn't even turn the fans on. The TPS checked out ok 0% at idle and 100% at WOT.

It has 02 lambda which always reads 0, 02 voltage which doesn't tell you much, fuel % trim which was 0.8% on bank 1 and 1.6% on bank 2 (no idea what that means), and calculated load value of 2.0% (no idea what that means). I want a AFR reading like 10:1, 12:1 etc but don't see that. I hope that 0.8% is not the real AFR reading.

[skyphix]

Originally Posted by cebra

They were supposed to tune it as a manual but honestly they are not doing a very good job of making me feel comfortable about the tune as they didn't even turn the fans on. The TPS checked out ok 0% at idle and 100% at WOT.

It has 02 lambda which always reads 0, 02 voltage which doesn't tell you much, fuel % trim which was 0.8% on bank 1 and 1.6% on bank 2 (no idea what that means), and calculated load value of 2.0% (no idea what that means). I want a AFR reading like 10:1, 12:1 etc but don't see that. I hope that 0.8% is not the real AFR reading.

Yeah, the only ones that will actually pull a tune and show those tables for these GM ECu's are ones like HPTuners with their adapter (there are a few others, just an example) and that would be approx $400 - not worth it unless you want to be able to apply/modify tunes yourself. You could get just the hardware for logging purposes but thats $300 of the $400 to tune it yourself.



Fuel trims of < 5% are normal so don't worry about that - thats just how much the fuel is being auto adjusted to keep it near stoich. The only way you can get an AFR reading like that that's accurate is with a wideband O2 sensor - narrow bands are only accurate at 14.7 (stoich) - other than that, they pretty much only say "RICH" or "LEAN." Depending on the car, and the software you use, you can occasionally get a commanded AFR and a calculated AFR but the only accurate way to get what the AFR actually is, is with a wideband O2 sensor. Factory ones are narrow band.


Let us know what the tuner says - I am invested now!