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3sgte goes lean


Toliski

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Hello guys, I drive my 3s for 3 months now, I make the tuning myself to my g4+ and it's working fine. 

Yesterday I have weird problem. 

If you go at (0:40-0:60 and 1:26-1:38) at my log you can clearly see at steady throttle that the Afr is all over the place and the Map too.

Mr2.pclr Mr2 Log.llg

And at another log you can see that I hit the throttle but the engine not responding for some seconds.

 

Screenshot_20190310_171339.jpg

What do you think think guys? 

Fuel pump problem? 

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Doesnt look fuel pump related. Its actually flowing less fuel at that ~1400rpm 1% TPS range than you are at idle. 

If you run that same check but at say 20% tps (so 3-4k rpm) does it show the same behaviour?

Looks to me like your fuel map isnt granular enough at idle map values (30-35kpa) and so its bouncing around a bit as it goes too high/rich -> too low/lean and cycles back and forth between the 2 states. Your idle seems ok but its at ~0.87 lambda whereas that 1% tps rpm is between 1 and 1.15 which is quite lean. try increasing the fuel table values in this region by a few points. you may need to add in a line at 30kpa as well and let it interpolate as a starting point.

image.png.bf0c67cd0b8be32092afd2f576e3e584.png

The other thing that might be at play here is if your injector dead times are wrong. Are the numbers you have in there from a reliable source and/or tested? You also have no short pulse adder numbers which can help this kind of behaviour too as at ~1 ms you might be on the edge of non-linear injector flow.

you've also got launch control permanently enabled when the car is under 15kph (VA1 config). This isnt directly impacting it but its stopping closed loop lambda kicking in and probably some other things.

If none of the above help, disable ignition idle control and swap idle, lambda correction etc all back to open loop/disabled so you can rule out these systems "over-reacting" which can cause cyclic rpm issues like this.

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4 hours ago, cj said:

Doesnt look fuel pump related. Its actually flowing less fuel at that ~1400rpm 1% TPS range than you are at idle. 

If you run that same check but at say 20% tps (so 3-4k rpm) does it show the same behaviour?

Looks to me like your fuel map isnt granular enough at idle map values (30-35kpa) and so its bouncing around a bit as it goes too high/rich -> too low/lean and cycles back and forth between the 2 states. Your idle seems ok but its at ~0.87 lambda whereas that 1% tps rpm is between 1 and 1.15 which is quite lean. try increasing the fuel table values in this region by a few points. you may need to add in a line at 30kpa as well and let it interpolate as a starting point.

image.png.bf0c67cd0b8be32092afd2f576e3e584.png

The other thing that might be at play here is if your injector dead times are wrong. Are the numbers you have in there from a reliable source and/or tested? You also have no short pulse adder numbers which can help this kind of behaviour too as at ~1 ms you might be on the edge of non-linear injector flow.

you've also got launch control permanently enabled when the car is under 15kph (VA1 config). This isnt directly impacting it but its stopping closed loop lambda kicking in and probably some other things.

If none of the above help, disable ignition idle control and swap idle, lambda correction etc all back to open loop/disabled so you can rule out these systems "over-reacting" which can cause cyclic rpm issues like this.

I have Rc1000 PL-4 injectors the dead times was from RC site and they don't provide short pulse adder.

I will try to disable CL idle and I add to fuel to see how it reacts and I report back. 

My guess is the FPump because of the sudden start of the problem. 

The most of the Map is tuned with quick tune and it has very stable Afr before that behavior (before 2 3 days) 

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47 minutes ago, Ducie54 said:

Have a try of this. Just do cold start to hot log with no revving. Post the log and ill made some changes. 

https://www.dropbox.com/s/pujt0q1nn4ar2dy/Mr2 test.pclr?dl=0

Well I try it. You can see at the begining we go well for a couple of secs, At log it not very clear but after 1 minute you can see the miss fire at Rpm signal. After 3 minutes its a lot of worse and after 4 5 it bearly runs. https://drive.google.com/open?id=1nUXEziAW0C9OdOhCEDO7dK1p0namQayk

Then i try with some load at second log you can see steady throttle same thing. When i left the throttle it shut down and i crank but nonthing!

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https://www.dropbox.com/s/yf9uxqr0106i08w/Mr2 test-2.pclr?dl=0

 

Increase the fuel table numbers so AFR is close to target at idle. 

Idle ignition less aggressive and more fuel. I think those injectors are not very linear at small pulse widths. By lower ignition at idle you need more fuel/idle base % to keep idle speed up  

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28 minutes ago, Ducie54 said:

Also in the log at 1mim 40 your battery voltages changes a lot any idea why?

I have small alternator wheel and at low rpm i have that problem.

46 minutes ago, Ducie54 said:

https://www.dropbox.com/s/yf9uxqr0106i08w/Mr2 test-2.pclr?dl=0

 

Increase the fuel table numbers so AFR is close to target at idle. 

Idle ignition less aggressive and more fuel. I think those injectors are not very linear at small pulse widths. By lower ignition at idle you need more fuel/idle base % to keep idle speed up  

Well You can see again the miss fire if you check map signal rpm voltage drop (due to rpm change) and after a sec the wideband folows. its better now beause it doesnt goes very lean but the miss exists.

I make a ride log too https://drive.google.com/open?id=1nUXEziAW0C9OdOhCEDO7dK1p0namQayk

I make a video for you you can find it at same folder at my Gdrive

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ah, you didnt say it had a misfire. that combined with the sudden start of this problem means i'd check the plugs for damage, strange wear, etc.

The last log your fuel number looks pretty good for near idle @ ~0.95 so I doubt you have rich/lean misfire happening now so check plugs, coils, HT leads, etc - whatever ignition system you have on the engine.

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It also doesn't help that the slope of your dead time figures are out and you have alternator issues. Its like it dropped a phase inside the alternator. 

 

In all honesty i would sort out your voltage issue and injector dead time values before worrying about anything else. Will save you a lot of headacks

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25 minutes ago, cj said:

ah, you didnt say it had a misfire. that combined with the sudden start of this problem means i'd check the plugs for damage, strange wear, etc.

The last log your fuel number looks pretty good for near idle @ ~0.95 so I doubt you have rich/lean misfire happening now so check plugs, coils, HT leads, etc - whatever ignition system you have on the engine.

 

20 minutes ago, Ducie54 said:

That last Ducie2 log is way rich. You need to get fuel closer to target of .95 I would suggest you pull the plugs out and clean them. 

Also you running peak and hold injectors. Are you still using a ballast resistor?

I don't know adout the injectors, the engine running with same setup years. 

 

I will try to change the plugs and coils one at a time to see. 

 

I suspect the fuel pump because some times I push the throttle and it doesn't respond. That behavior start before two days suddenly. So I believe its not tune related. I have logs before let's say a week and it's running fine. 

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7 minutes ago, Ducie54 said:

Same setup you blew the motor on racing the bike?

You have no accell enrichment 

Hahaha!!! 

Not exchact the same I make some changes and I don't WOT it until I will take it to a tuner.

I rebuilded again and it running fine 3 months now.

Before 3 days that weird problem start. 

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