OK, thought I understood some of this stuff. Using 7730 ECM, Speed Density, basically stock AUJP (EGR delete, VATS disabled), $8D. VE Tables for this issue are unchanged from stock AUJP. TPI Using 22# injectors with Injector Flow rate set at 22.98, which gives BLMs of 125-129 in all BLM cells --- except for idle (cell 4). Idle speed set at 650 RPM in ECM and that’s right where it idles (650-675 RPM) steady.

Here’s the problem I can’t solve – At idle while cold when in open loop, INT = 128 and BLM = 114, cell 4. This would indicate it’s rich and can smell gas fumes for a mile. So while emulating with AutoProm and monitoring with TunerPro RT, I select VE table rpm cells 400-600 for all KPAs 20-100 and multiply by .9 and idle on that. I can hear the engine change slightly but INT and BLM do not change. Multiply by .9 again and can hear idle change more radically and it runs rough and nearly dies, but again no change in INT or BLM.

Stupid questeoin, but if this is not how to lean out a rich idle in open loop, would someone please tell me how to do it? Clearly the engine is seeing the idle changes as verified by how it runs, but the changes are not being reported in INT or BLM.

And then should not those VE idle changes also be effective in closed loop?

 

The integrator and block learn multipliers won't change in open loop. For the integrator to move closed loop has to be in affect (and not in PE mode). For the block learn multiplier to move learn has to be in affect.

RBob.

 

Thanks RBob, but if INT and BLM don’t change in open loop, then back to the question: How can idle rich/lean be changed/adjusted in open loop? Surely it can be.

Isn’t it done via the VE tables? If not, then how is it done? And how does one know what effect the changes had if INT and BLM don’t change?

I can’t be only one in this forum that doesn’t understand this. Do we just blindly accept in open loop the way our proms are programmed meaning that we only change/tune idle in closed loop? Anyone, would really appreciate some help on how to do this. Thanks!

 

The VE tables are adjusted with the engine at operating temperature. Usually using the BLM values.

To change the fueling when in open loop, change the open loop AFR tables.

Do you realize that you posted in the DFI & ECM board?

RBob.

 

Sorry for the wrong post. Should this be in “DIY Prom”? I read the description of this forum and the last sentence is: “Fine tune your Third Gen computer system for top performance.”

Do I need to move it, or do you do it as Moderator, or do I repost? Thanks.

 

You would get more response in the DIY_PROM section. Which is a better location for your question. I can move it for you if you'd like. I brought it up as you asked about the lack of response to your thread.

It's funny about the last sentence of the board header you posts: Fine tune your Third Gen computer system for top performance.

I don't ever recall that being there...

RBob.

 

RBob - That sentence is why I posted here. Maybe that sentence should be moved to DIY. I'll repost it in DIY and you can delete this one. Thanks.