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Help with cold start E38 L96 6.0 with Comp Cam 54-459-11

Practical Reflash Tuning

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I got my car running pretty good but on cold start I seems to lack power. Im sure theres a table or tables that I need to edit for this and have tried but to no avail. Disregard the title as This is before I made adjustments. Still has stock injectors.

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Can you provide a better description of the problem? Is it that the engine won't fire / start when not already warmed up? Or only on very cold days? Or does it start ok, but run rough until warmed up?

I'm particularly confused about "seems to lack power". Under what conditions? I wouldn't expect to go wide-open-throttle on a cold engine, or do you mean cruise / part throttle seems less powerful (i.e. requires more throttle) while under normal operating temp?

It's a manual car , so when warmed up it idles fine and I can just release clutch to move, when cold the idle isn't as smooth and also will stall with clutch engagement.

You need to know lambda value during warming up. If it's too rich or too lean the engine will likely stall once clutch is engaged. It's better be within 0.95-0.88 region for stable operation, usually outside of this values it's stalling. Other important factor is ignition as it should be increased when engine is not fully warmed up - there is usually another table to address it.

Yes I agree and it is lean on cold start so my question is where do I adjust that. It has to be a cold start table or at least 1 or more table that adjust based off engine coolant temp or run time. I did attach a log file that shows the lambda on cold start in the first post. I'm running 2008 gm e38 (2008 g8 ecm)

I know your title says speed density, but I think the Air Calc Mode says "normal", so I modified the MAF scaling, as the MAF value is what changes as the engine warms up and the AFR returns to the commanded value. Try this and see if it makes a difference.

The issue might be your VE table, as that has a few lean-indicated bumps in the 55kpa / 1000 RPM range. That table seems like it could be smoothed.

Attached Files
  • 240sx-Speed-Density-E38-L96-New-Injector-Tune-v2-modified.hpt
  • Attachments may only be downloaded by paid Gold members. Read more about becoming a Gold member here.

Ok cool thanks, I'll try it out, also I need to change that as I am fitting a turbo on and no longer running MAF sensor once installed. Thank you for your help, greatly appreciated as I am still learning. Also where did yoy see the "air Calc mode" - normal? I see on mine it says speed density under OS - speed density air mode = applied.

Attached Files

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