VEMS Community Forum
VEMS => Software => Topic started by: fphil on August 28, 2017, 01:47:51 pm
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With 1.2.38 when I set "Fuel resume RPM = 1500", the fw resumes @ 1600rpm. The VT gauge from 0 then shows 2.37ms ad the logviewer 1.31ms. :-[
In your case, have you noticed so?
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Do you have a log of this happening?
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This was to know if some has noticed the same matter for the fuel resume value and the discrepancy PW gauge value w/r PW log viewer value, and if a bug report is necessary.
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I thought I had noticed some change in the overrun fuel cut resume. On 1.2.31 my overrun fuelcut was smooth as butter. Not so much with 1.2.38. I'll have to look at logs
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I thought I had noticed some change in the overrun fuel cut resume. On 1.2.31 my overrun fuelcut was smooth as butter. Not so much with 1.2.38. I'll have to look at logs
+1
Besides the logic for the RPM and/or Map condition on fuel cut is not obvious for me. I would be happy to see the fw code :D
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My understanding of how it works (I haven't reviewed the code, just going by experience)
If the MAP is less than the "Fuelcut below" then fuel is cut. Not affected by RPM at all, this is just across the board.
If the RPM is above Fuelcut RPM and TPS is below "Idle Threshold" then fuel is cut
If the RPM is below Fuel Resume RPM, fuel is normal.
From my experience, it usually doesn't work well to have fuelresume be less than 1800. Usually I set it around 2000-2100. It very much depends on how fast the engine slows down. The faster it slows down, the higher you need fuelresume to catch the idle in time.
There's nothing in the change log between 1.2.31 and 1.2.38 regarding overrun fuel cut, so if you can get a log with both firmware versions and make a detailed report in the wiki about it, someone will look at it and either explain the difference, or find/fix a bug.
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Per example I do not understand this VT screen
(https://i11.servimg.com/u/f11/15/63/46/75/fuel_r10.jpg)
fw 1.2.38, 2 values for PW (this is an old one), fuel resume at the wron value (TPS=0 non seen). Do you have the same concern? or do you check your log?
This may be some impulse noise on TPS, but I guess that the trigger for TPS threshold is filtered somewhat
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Fuel resume at 16xx RPM, not 1600 exactly. If you want to wait until 1599 RPM, set to 1500.
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ok. In fact starts to resume at a little higher RPM, may be 1699 rpm? anyway I can live with that, it suffices to know. What about the 2 values of PW? Is it the same for you?
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ok. In fact starts to resume at a little higher RPM, may be 1699 rpm? anyway I can live with that, it suffices to know. What about the 2 values of PW? Is it the same for you?
Look in Calc Model group (Shift +5) and you will see "VT Pulse Width" and "ECU Pulse Width" perhaps this is what you are seeing?
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Look in Calc Model group (Shift +5) and you will see "VT Pulse Width" and "ECU Pulse Width" perhaps this is what you are seeing?
Yes of course I am aware of the calc model. There is there a third value, ( the calcl bvalue is 2.67)
(https://i11.servimg.com/u/f11/15/63/46/75/pwvalu10.jpg)
Have you quoted the same gaps? From where this 2.25 ms (or mS) comes from? This value may be the effective pw without the response time, who knows?
I guess not too many users look at the logs ;)