Running rich, BLM ok?

[87gninpa]

Can a car be running rich if the BLMs are always in range (128-130 throughout driving range & idle)? O2's are 830-860 @ idle and car gets crappy mileage (16 mpg last tank - split highway/city). Smless rich at idle but theres not cat so that doesnt reall say much. Plugs look OK, oil smells faintly of fuel. All other SM values in range (@idle):
AF - 5-6
INT - 128
BLM - 130
TPS - .43
IAC - 22
Crosscounts - Locked at idle, but move quickly through entire range anywhere off idle (open loop idle - TTChip)

Car runs great, but spools slow and just uses a lot of fuel. Maybe nothings wrong, just wondering if its possible even though all numbers look OK. I know O2's @ idle are way high, is that normal for a TT chip?

 

[TurboDave]

You're running an "open loop idle" chip which explains the extremely rich O2 numbers at idle, and the locked cross counts. While open loop idle modes are nice for a smooth idle, but as you can see/smell, they cause a rich idle condition. While driving (anything above idle) you're blm's are great, and you're O2's are likely all over the place as they should be.

Unfortunately I don't know enought about TT chips to tell you if there's a way to lean down that open loop idle fueling, as I run Extender and Commander chips in my GN's. They have an open loop idle available, but it's an option that can be turned on or off as desired.

 

[87gninpa]

Yea, I figured it was because of the open loop idle in the TT chip. Just thought it was strange that BLM @ idle are perfect but its dumping a ton of fuel. Otherwise it runs good, maybe Ill look into another chip.

 

[TurboDave]

The BLM you're seeing at idle is what was learned the first time the chip was powered up. After that there is no more learning because of the open loop function that takes over after the "first" startup.

 

[aminga]

The newer chips you can set it to be Closed loop idle but you have to have a 5.7 or a 6.1 chip to do it.

 

[87gninpa]

Messed around with the car a bit yesterday. Set the translator to a leaner idle and it worked, but the car idled like crap. O2's dropped, but the BLM rose and idle was nowhere near as smooth. I guess these cars like having a richer idle. I did bump the fuel psi up a couple of pounds and now idle O2's are closer to 800 so that helped a bit, still idles smooth. Think I need a new fuel psi gauge though, the one on the rail is probably toasted, I get very inconsistent readings.

 

[87gninpa]

Borrowed a nice Snap On fuel injection test kit from a guy at work. While my rail gauge read 44 psi line off, the snap on gauge read 48. Bumped the fuel pressure down to 43 with the snap on and car runs a lot better, seems to pull much harder under boost than before and the boost comes on quicker. Two things I noticed though; 1. BLM is 136 @ idle now, I know that still within the ECM's range and BLM is 129-131 in all other cells, should I just leave fp where it is? Id hate to adjust for BLM at idle and ruin the way the car is driving now. 2. When I had the snap on gauge hooked up it was steady with the vacuum line on, but when removed, the gauge fluttered quickly back and forth about 1 psi, is this normal?