MicroSquirt.com read only forum (Jan.15,2018)

I'm about to just start running the beta code!

Remember to change the Decel value from 100% to about 60% and play with X more than Tau. I found I had to reduce X to about 22% so AFR's didn't get a little to out of hand.

Other than that and a couple of comms issues, it's great!

OK I really sat down with this and tinkered. Results are much better. My AFR now tips out at 18:1 on the lean and 12.2:1 on the rich during accel events. Car feels much better between shifts because of this. Anyhow is this as good as it gets with traditional TPS based accel? I'm guessing so if so much work is going into the new X Tau code. Anyhow here are my settings now.

100% TPS based

154 8
80 6.5
40 4.0
10 1.7

TPS dot 2.5
Decel 100


I also set my Accel time from 0.2 to 1 second. with a taper time of 0.1 second. This seemed to help some also. I guess I can set my decel lower again too.

Any other ideas guys?

Thanks,
A.J.

It looks like you are making progress.
Check on your logs to see what the max TPSdot is.
I rarely see over 70 so have that as the top bin.
I like to have a close groop at the small dot's since that seems to be most sencitive like

TPSdot
--------
60
30
5
2

Cool method with the slider mops, I never tryed that.
My main problem with MAPdot was that when I had enough sencitivity for off idle I would get unnintentional activation in mid to high power operation that casued bucking. There was too much MAP noise on my engine.
Also decel is not activated by negative MAPdot.

I was stuck in traffic today and my engine got warm enough that my fan was kicking on and off. At this point my accel was getting very temperamental going real lean again. Grr. Is there anything temperature based I can do?

A.J.

did you do a datalog ? if you are stuck in traffick, common problem is IAT heatsoak. once it readding high numbers (i get problems ar over 40 deg C) it leans out the mixture, in extreme cases (like IAT reading of 60 deg C, which is common in heavy traffick) engine will be popping lean, etc...

mops,

This worked quite well. I'm am now running 100 MAP based accel. There are still some situations the lean out but nothing like before. My MAPdot is about 135 to keep from accidentally triggering. I'm still having issues with off idle accel and if I slam the gas under load it leans on me. I'm guessing I need to throw in some TPS based accel too to cover the top end more. I noticed my max accel is about 5ms of fuel unlike before. More importantly I can now drop the clutch and tap the gas like I'm used to doing to get rolling. Before it would shudder and sometimes stall. So this makes me happy. I like running low RPMs and letting the clutch out quick to get going. Now I need to look at why my engine stumbles after I start it up when warm.......

A.J.

mops wrote:setting will difffer from engine to engine.
my guess is 20ms is flooding engine...
If i was you i wouldnt bother with AE at all, just get 2.672 code and tune with x-tau.


put mapdot values to simulate logaritmic curve. try to overshoot (i think 20ms is massive overshoot). ... you might wanna even start with sometinhg random like 2, 5, 7, 9ms....set all tpsdot values to 0.

set the slider to 100% tps (i.e. accelenrich = 0)

rev the engine. notice behaviour. try revving engine from like 2k rpm onwards. idle point is not a good place to start AE tuning. aswell, when you rev, try to be consistent with throttle... including consistent speed.

now move the slider to, say 30% map, 70% tps (effectively 30% mapdot values). repeat testing. notice difference ? yes ? no ? better, but still not there ?

move the slider some more depending on the behaviour. repeat...

Glad to hear.

I think threshold of 135 is your problem there. it should be lowest possiblt without triggering false. so basically do it like that:. warm up your car and idle. make a datalog, observe mapdot on the datalog. it will swing, in my case +-20 all the time. sometimes 25. so i set my treshold to 35 and that is working fine for me. that will take care for your off idle response.

aswell, i'd add few more degrees of timing just abouve idle - that makes good strong off idle response and you can pull out of light without reeving engine and still pretty damn quick.

re warm stumble when I was tuning my car i noticed it aswell. the problem with my engine is that my engine like alot of afterstart enrich on cold, but when hot afterstart enrich can literaly flood the engine. so try less afterstart enrichment. less value for longer. incerase warmup bins to compensate at cold starts....

damn, i think i should be a pro tuner....

I tried a lower value for MAPdot and well although at idle it may blip to 30 at WOT MAPdot jumps to 120. Is this normal? Or do I have some other issue like timing?

I'll get an updated datalog tomorrow and post.

A.J.

Oh yeah my afterstart. I set it to zero and also lowered my warmup bins by 5% and yet when I tried to start for some reason as soon as it fires the fuel jumps from a normal 7MS to something like 16ms then engine just stumbles untill it jumps dow to something more normal like 4ms. I'll try to datalog and post.

A.J.