Shallow Bay

iTrader: (3)

I just finished installing both a LC-1 and DynoTune wideband gauge in my car and now I have a question. What is the normal AFR you should see at idle? My car has a couple of bolt-ons (lid, ported throttle body, long tubes, true duals) and it's currently running in open loop. I let the car reach full operating temperature and while the commanded was 14.37, both the gauge and EFILive read around 16.37. I double checked the intake and exhaust for leaks but I didn't find any. I then performed another free air calibration to see if it would make a difference but it didn't. Would a couple of bolt-ons really make it run that lean at idle or is un-metered air getting in somewhere? Any help is appreciated.

brad8266

iTrader: (23)

If you are stuck in open loop then there will be no learning of fuel trims for AFR. Normally once it warms up it enters closed loop and the PCM will use fuel trimming to keep AFR at 14.7 during idle and part throttle operation.

If you are in open loop then your actual AFR will depend on what your airflow tables are set to. Your stoich setting will have no affect in open loop, it will fuel solely based on VE/MAF/OLFA. Since you are too lean you probably need to raise the values in your VE/MAF table and check your OLFA table.

You could check for intake leaks if you think you have one, but yes a few boltons can cause a good increase in airflow, thus requiring an increase in VE/MAF values.

Shallow Bay

iTrader: (3)

How much do you suggest I add to the VE table?

brad8266

iTrader: (23)

The percentage difference between what you want and what you are getting. 16.37/14.37 = %114. That sounds like an Ok starting point.

Shallow Bay

iTrader: (3)

I just realized that the AutoVE tutorial I'm following has you add 15% to the VE table. I feel like that a pretty good starting point. Thanks for the help.

Frost

iTrader: (45)

What reason is there to run open loop on a stock car?

brad8266

iTrader: (23)

None.

2002_Z28_Six_Speed

iTrader: (19)

You dialed it in and aren't going to mess with it.