Running way to lean in cold open loop. How do I fix it?

[1Hotbird]

As you can see when I give it a little throttle it runs lean. How do I go about fixing this? As you probably figured out I have a LC-1 wideband.

I messed up and did not record the feedback from the Lc-1 but it mostly follows the commanded fuel.

The second log has pid's for Auto Ve and it shows the LC-1.

2532

2533

2534

Im pretty sure I have to change my b3605 table but why dose it only use this table with throttle? it snaps back to good fuel ratio when their is no throtle. Dose it get its idle fuel ratio from another table?

[joecar]

Hi 1HotBird,

The left half of your B3605 contains EQ 0.702-0.821 (~AFR 17-20)...
you should change these cells to EQ 0.99 or 1.01 (AFR 14.78 or 14.49) .

The PCM uses the richer of B3605 and B3618 [when PE is enabled] during open loop... in your case, PE is not enabled, so the PCM looks at B3605... you can see this if you enable scantool->tunetool PID linking.

In your log, when AFR goes to 18+, the FTC # is 22 which is supposed to indicate WOT, but your TP is only 5-6%... I can't tell why, but the PCM goes to FTC # 22 for some reason.

Cheers,
Joe

[TAQuickness]

IIRC, when in OLSD, you only have 3 FTC's: idle, WOT, and I can't remember the other one off the top of my head. Been a long time since I've done any tooning [sic] that required monitoring of the FTC's.

[SV8346]

From what i can see from the logs there is a few problems with this tune, first is B3605 is extremely lean on the whole left side of the table. Second problem i have found is the timing tables (B5913 and B5914) are very erratic, try smoothing out the timing tables a bit and also drop your base timing(B5932 and B5933) down and idle timing down a bit, your trying to give it 35 degrees timing at idle which is way to high IMO.

[1Hotbird]

Just a question but someone mentioned it might be set lean because I have alot of overlap in the cam? Can the overlap fool the narrow and or the wideband into a false lean reading?

What is FTC #22??? (Sorry Im new)
Also How do I do this, enable scantool->tunetool PID linking.???

Thanks


Hi 1HotBird,

The left half of your B3605 contains EQ 0.702-0.821 (~AFR 17-20)...
you should change these cells to EQ 0.99 or 1.01 (AFR 14.78 or 14.49) .

The PCM uses the richer of B3605 and B3618 [when PE is enabled] during open loop... in your case, PE is not enabled, so the PCM looks at B3605... you can see this if you enable scantool->tunetool PID linking.

In your log, when AFR goes to 18+, the FTC # is 22 which is supposed to indicate WOT, but your TP is only 5-6%... I can't tell why, but the PCM goes to FTC # 22 for some reason.

Cheers,
Joe

[1Hotbird]

Can you break this down for the new guy? IIRC,OLSD,3 FTC's???
Thanks


IIRC, when in OLSD, you only have 3 FTC's: idle, WOT, and I can't remember the other one off the top of my head. Been a long time since I've done any tooning [sic] that required monitoring of the FTC's.

[1Hotbird]

First things first I need to get my mind wraped around the fueling side of the computer, then I will move on to the Spark.

Ive been told that because of the overlap in my cam it has a "natual EGR" effect, there for needing more advance at lower RPM's?? Can anyone tell me if this is true????


From what i can see from the logs there is a few problems with this tune, first is B3605 is extremely lean on the whole left side of the table. Second problem i have found is the timing tables (B5913 and B5914) are very erratic, try smoothing out the timing tables a bit and also drop your base timing(B5932 and B5933) down and idle timing down a bit, your trying to give it 35 degrees timing at idle which is way to high IMO.

[SV8346]

Also How do I do this, enable scantool->tunetool PID linking.???

Thanks

Open TUNE tool then click on "EDIT" up the of the page then click on "PROPERTIES" then in the properties window that opens click on the "SCANNER" tab, there you will see "Highlight scan tool selection in tuning tool maps". Make sure this is selected.

From there on when you have scan tool open and tune tool by putting the cursor on a select point in the log it will highlight that point in the tune.



Can you break this down for the new guy? IIRC,OLSD,3 FTC's???
Thanks


IIRC=If I Remember Correctly
OLSD= Open Loop Speed Density
FTC= Fuel Trim Corrections (I think:help2: )

Ok to get you head wrapped around the fuel side of things first then i would strongly suggest you richen up the whole left side of your mixture map(B3605) before you lunch your engine.

Upload this tune and give this a go, i think you'll find it will idle allot smoother and also it wont run anywhere near as lean as what it was.

[joecar]

From the scantool manual pdf (page 137):
http://img134.imageshack.us/img134/9521/ftcoc2.png