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Toliski

Unstable Idle

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The bouncing idle doesnt appear to be caused by idle control, you idle valve control actually looks pretty good.  A couple of things I notice;

  1. You have quite a lot of dwell scatter, this indicates the ecu is getting bad engine position information, which could mean the ignition timing is bouncing around too.  Can you do a triggercope at normal idle speed and attach here.  Here is a quick video showing how to do it.  https://1drv.ms/v/s!AiYbYlZQuRHPmieMTkwQDCXEb2LY
  2. You obviously have very large injectors so a small injector pulse width at idle, this could possibly mean your injectors are becoming erratic and some cylinders are getting less fuel than others.  As a quick test to eliminate this you could adjust the 4 highlighted cells in the Lambda target table - set them all to 0.95 and if idle smooths out then this could be your problem.

s8op3s8.png

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Trigger Scope Log 2018-05-23 1;05;22 pm.llg At 1000Rpm

I just see that my injector latency times are off.
This can be a problem at idle?
I have PL4-1000 RC injectors and i have no Short pulse times.

I just see my unstable Dwell time.

My triggers seems ok. 
my Batt voltage is 13.9-14.0
Why my dwell is so unstable?

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Hmmm, thats weird, the triggerscope looks ok, I really expected to see something wrong that would explain the jumpy dwell.  It wouldnt hurt to check the distributor/CAS doesnt have lots of backlash or the sensor has come lose inside etc.

Did it help idle when you richened up the target table or was it still similar?

Actually looking at the log again the idle doesnt actually look too bad.  Can you explain a bit better what you mean by "I cant make my idle to stabilize"

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1 hour ago, Adamw said:

Hmmm, thats weird, the triggerscope looks ok, I really expected to see something wrong that would explain the jumpy dwell.  It wouldnt hurt to check the distributor/CAS doesnt have lots of backlash or the sensor has come lose inside etc.

Did it help idle when you richened up the target table or was it still similar?

Actually looking at the log again the idle doesnt actually look too bad.  Can you explain a bit better what you mean by "I cant make my idle to stabilize"

I try to make another log later with the richer idle to see if its better.

If i try to idle at 900 is unstable if i try to idle at 1000 its a little better.

 

I run COP setup with stock distributor. The distributor position is as you suggest me at older topic at middle. 

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Here is my idle log https://drive.google.com/open?id=1yKSws-qE7iY1v1xnx-aSL3u576guCcY5

And here is my map. https://drive.google.com/open?id=1bMhgGjba2iPem8h45GIZyJ6PmP3wjlic

After i correct my injector latency times my AFR changed so i correct only the low load area until 2500rpm.
I am at Break in period i cant tune further until i do a few more miles.

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I have merged your threads since they are all about the same problem.  

2 hours ago, Toliski said:

And why my Dwell isnt stable

 

On 5/23/2018 at 10:30 PM, Adamw said:

It wouldnt hurt to check the distributor/CAS doesnt have lots of backlash or the sensor has come lose inside etc.

 

 

Have you checked this yet?  Dwell scatter means the ECU is not receiving regular tooth events from the CAS.  Your triggerscope looks ok so that suggests the problem is mechanical rather than electrical.  Most likely there is excessive backlash in the drive system somewhere, loose cambelt, tensioner, sprocket etc...

 

2 hours ago, Toliski said:

Hello guys can anyone explain me the bouncing idle?

Did you increase the lambda target like I suggested earlier?  Some of the idle problem is possibly related to the same problem that is causing the dwell scatter so I would get that fixed before I spent much time trying to fix the idle.

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I just check my old logs before i rebuild my engine and i see that Dwell scatter exist but the bouncing idle not.
I try to made the idle area more rich close to 13.5AFR. But it doesnt help.

My new Map https://drive.google.com/open?id=1a3p3RJOU_nH7owqpFnhMyk9iH-74sEcX

New Log https://drive.google.com/open?id=18r0eukVk2hZE3p2AeW_nmUnCf3RcPgfm

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I dont see any obvious problems in the log.  Have you checked your base timing is correct?  If you lock the timing and watch the pulley with a timing light at idle, is the timing stable or is it bouncing around?

The only thing I see that is a little weird in your log is that your idle valve is working at 5-20% DC.  In our ST185 base map we have the minimum clamp set to 20%, usually the reason we put a clamp like that in the base map would be because the idle valve control becomes erratic below that DC.  So I suggest you try closing the throttle blade a little and adjust your base position table so that normal idle valve position is around 50%.

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