Rich Idle

[patrickbrown]

Hey all,

I'm a bit confused about how to get started with my tuning. I have my engine starting reliably and have my IAC set to give me a warm idle of about 900 RPM. My O2 is reading 12.1 even though the AFR table lists a target of 13.0. I've been fiddleing with the VE values around the curser but am not seeing any change. My table had values in the 60s at that MAP/RPM range. I dropped them to the 40s and nothing.

I also tried the Autotune feature in TunerStudio (I have the registered version). I don't see that is is doing anything. Can Autotune tune the idle?

I also noted that my idle MAP reading at 900 RPM is about 60 kPa. That seems high.Should I be concerned?

[Matt Cramer]

Hey all,

I'm a bit confused about how to get started with my tuning. I have my engine starting reliably and have my IAC set to give me a warm idle of about 900 RPM. My O2 is reading 12.1 even though the AFR table lists a target of 13.0. I've been fiddleing with the VE values around the curser but am not seeing any change. My table had values in the 60s at that MAP/RPM range. I dropped them to the 40s and nothing.

That may be a sign of too much opening time. How much did the pulse width change?

I also tried the Autotune feature in TunerStudio (I have the registered version). I don't see that is is doing anything. Can Autotune tune the idle?

You can, but I prefer to tune it by feel and not by AFR numbers.

I also noted that my idle MAP reading at 900 RPM is about 60 kPa. That seems high.Should I be concerned?

High idle MAP readings are relative - if the engine has a wild lumpy cam, I've seen worse.

[patrickbrown]

I re-read the whole MS2 tuning doc again last night. It might be sinking in. Here are the results of this evening's tuning.

After the engine was warm I noticed that the PW was about 5.2. My AFR was still 12.1. I opened the VE table and selected a 3x3 section around my idle area. I increased the values until the map started to climb and the engine began to stumble. I then dropped the values past my starting point until the same thing happened. Then I brought them back up until I found the point where the MAP reading was lowest and the idle sounded good. AFR was still at 12.1.

Then I noticed that I forgot to set my O2 sensor to LC1. It was set at NB. I changed that and redid the tuning exercise above. My idle PW is now aout 4.2ish. Idle AFR is about 13.1.

The throttle feels good. There is no off idle stumble. The warm start is okay but not great. It usually starts without any throttle input but it struggles. I'd like to smooth out the idle a bit more. Maybe injector timing? This is a Ford V8 and I have the injectors for 1-4 on bank one and 5-8 on band two.

My idle MAP is still at around 60. My bins start at 20. Should I change those now or wait until I see them on the street under load?

I attached my latest msq with a log of my idle in case anyone wants to offer any feedback.

Thanks everyone,