Hi,

I have a problem, sometimes when I do a pull in a high gear the car feels "jerky", acceleration is not smooth.. like if the power is coming in waves..

So.. I did a log run with evoscan and I see that the timing is going up and down in intervals in a pattern like the one I feel when I drive..


4-10-4-9-5-10-5 ... etc..

I attach the log, it's from 3rd and 4th gear, especially in 4th you can see the ignition going up and down.. What could cause this? Knocksum is 0 in 4th gear.. But knock_flag is giving some data, don't know if this flag could cause this? You can also see a little bit of this in 3rd gear at about 5500 rpm but with 0 knocksum and knock_flag...

Please help!

 

Could it be so simple that it is the boost that is so fluctuating and that this causes the ignition to go up and down? (I will lower the boost a bit tomorrow by the way)

 

I don't thinl ustable boost explainsit, it shouldn't go as low as 4 degrees acoording to the ignition map.. and maybe not as high as 10 degrees either... is it octane is 100 all the way in the log..

 

I had this happen when the ECU interpolates between two load cells for the timing.

Mine posting the timing map?

 

my quess is you adjust 1 ignition high octane map way to high. so now the computer is going from one map to the other I would try to interpolate accross you cells and adjust the other maps as well.

 

I can't see squat on that graph. Post a better graph or post the log data.

 

I have changed all three ignition maps.. to have a relation between them that is like stock.. #1 is highest, just over #2 and #3 is a lot lower..

Here are my ignition maps.

https://www.evolutionm.net/forums/at...8&d=1177274493

https://www.evolutionm.net/forums/at...9&d=1177274502

I also attach ignmap 3.

 

Try to block the ignition map a little

 

can you attach the excel spreadsheet?

 

Here is the evoscan log.

 

It's staying in your first timing map, the problem is the timing values you have in there aren't smooth. The boost spikes, hits a high load where the timing values are negative, then as the car gets moving the load decreases and the timing comes back up but the values in adjacent cells are as far as 4* from each other so the ecu is bouncing back and forth between load columns which forces the car to make radical timing changes.

I bet the car is very slow for two reasons:

1) the overall timing is very low

2) the timing is shifting from low to high and back

I could get you fixed up pretty quickly and explain where and why I'm making changes so that you can learn during the process. Let me know if you're interested (see sig)

 

Do you mean that it is shifting between the timing maps? Or do you mean that it is using ignition map nr 1? How do you see that?

I am attaching the new ign maps I am flashing to the ECU now..

 

it's staying in the first map, watch the octane numbers stay 100


heading to the local autox to bust some *** should have some video tonight

 

mellon,

I dont think you can assume that Octane=100 means that it stays in the first map...

Certainly on my IX (could be different for the 8's, but I doubt it) the algorithm in the ECU interpollates between maps 1 and 2, and maps 2 and 3...

I have logged the memory bit that is the decision point for this subroutine and there doesn't seem to be any ryme or reason (that I can tell) for how the ECU chooses which set of maps to interpolate (ie 1/2 or 2/3)

I dont know why they have done it this way, as it does seem overly complicated, but thats the code...

 

good point and I know what you mean, I'm basing that assumption on the octane flag and the timing numbers from the log vs the 1st timing map. As a crutch some tuners set each map exactly the same to get a more predictable tune with the stock ECU. I still prefer to have a little less timing in the second map for safety.