Cool, so fixed...now it makes sense why I havent had an issue after I read through this thread.

aaron

 

Another interesting work from Tephra!

More resolution of IPW would be great. My idle slightly changes every second or so after I change to 700cc Sard injectors. I guess stock resolution would be enough for my case, but I guess more resolution should help smooth things out.

So I guess 91470715 V7 should use the same code as 96530006 ?

I am not sure if I understood this right, but after this patch, ECU can lower minimum IPW than the stock one, and the ECU can now adjust IPW more finely to hit the IPW target set by fuel related tables? (So I do not have to change any fuel related table?)

Is there any possibility this can hurt the dynamic range of IPW value? (Say reduced maximum IPW?)

 

I don't modify the resolution of the output IPW, only the resolution for the minimum IPW field.

 

Oh, ok. So it has more resolution to define the "minimum IPW".

So at idle, stock ECU gives some IPW = variable * output IPW resolution + minimum IPW (1.28 ms)

and this patch modifies the "y-intercept" of the linear graph if I understand this right?

 

No here is what Minimum IPW does (using 1.28ms as the min):

ECU calculated IPW : Actual Output IPW
0ms : 0ms
0.5ms : 1.28ms
1.0ms : 1.28ms
1.28ms : 1.28ms
1.5ms : 1.5ms
20.0ms : 20ms

 

Thanks for another explanation.

y-intercept is not right, it is just a flat area in the graph.

 

Its the absolute minimum that the ECU will drive the injectors down to

Other than OFF that is

 

I guess this minimum value exists because ECU is not perfectly real-time, and to prevent engine-stall (like fueling again when rpm drops to ~1000rpm when deceling)?

 

possibly.

but i think its more todo with the under-drive limit of injectors...

as the ID charts show, under 1.1ms things get hairy

 

Oh, I see. Some minimum pulse is required for stable injector operation. Transient response is not always ideal. Thanks for your patience and education.

 

Seems to have done the trick, now I have to go retune the car today on pump gas, then it will be time to put some E85 back in again!!!

 

Do you have the address for 88590015?

- Bryan

 

0x1102 for 88590015 should default to 1.024ms

88590015:
<table name="Minimum IPW #1 SHLL2->NOP (0x4908 -> 0x0009)" category="Misc" address="2af7a" type="1D" scaling="Hex16"/>
<table name="Minimum IPW #2 SHLL2->NOP (0x4908 -> 0x0009)" category="Misc" address="2af7c" type="1D" scaling="Hex16"/>
<table name="Minimum IPW #3 SHLL->NOP (0x4900 -> 0x0009)" category="Misc" address="2af7e" type="1D" scaling="Hex16"/>

<scaling name="IPW16:SHLL0" units="ms" toexpr="x*8/1000" frexpr="x*1000/8" format="%.3f" min="0" max="65" inc="0.008" storagetype="uint16" endian="big"/>
<table name="Minimum IPW SHLL0" category="Misc" address="1102" type="1D" scaling="IPW16:SHLL0"/>

 

Tephra, does this change the way Load is calculated at all, after tuning the car over the weekend I had to rescale my load tables out to 400, when max I was hitting with the ID1000s was 320, now I am hitting 350... Also it seems as if these bigger injectors are more prone to IAT compensation deviations at WOT as well, any input would be appreciated.

 

No it shouldn't - This *just* changes the lower bound on IPW.

It doesn't change anything else