after cruise idle unstable

[maccakpa]

Hi guys. my car (forester sti JDM) was tuned on id1050x and 272 camshafts before.
now i changed ID1700x injectors
kelford 282 in out camshafts with 1mm oversized valves
walbro 525 lph fuel pump
HKS m45iL sparks.

The problem is cold start and after cruise idle is terrible.

Could you guys please have a look at my log?

idle unstable.llgx

tuned 1.5 bar 98 octane.pclx idle warmup 2.llgx

[Adamw]

The log files doesnt seem to match the map.  For example the lambda target is 1.00 in the log but it is 0.905 in the map.  

The lambda is not even close to target so that would be the first thing to correct.  Why is the injector size set to 1600cc if it has 1700's?

Also, ID1700's dont have very good short PW behavior and for this reason ID dont recommend using them with gasoline where low flow is important, so dont expect miracles. 

[maccakpa]

thank you for your feedback Adam,

the main problem is cold start issue. Car drives okey while cruising.
Cold or warm start ups are most likely too rich. and i do only have 1 chance to start car with wide open throttle.  Otherwise car goes too rich and doesnt start up
 

[Adamw]

As a test, try turning off wall wetting compensation and zero out the short PW adder table.  

[DerekAE86]

55 minutes ago, Adamw said:

As a test, try turning off wall wetting compensation and zero out the short PW adder table.  

I'm curious, what's the theory behind this test?

[Adamw]

16 hours ago, DerekAE86 said:

I'm curious, what's the theory behind this test?

I suspect the unstable idle is possibly due to the SPWA as the lambda bounces up and down by a whole lot more than the reported effective PW.  You can see his reported Eff PW is bouncing between about 0.5 and 0.6mS (this reported value doesnt include SPWA).  If the injector was perfectly linear then 0.6ms would be 20% more fuel than 0.5ms.  If you add the SPWA figures on to that - at 0.5PW the SPWA is -0.066 and at 0.625PW the SPWA is +0.046 so you actually end up with a final PW of 0.434ms for the commanded 0.5 and final of 0.646 for the 0.6 commanded, or you could say 48% extra fuel/PW.  Obviously those adders are there to compensate for an injector that is not perfectly linear, but perhaps those or the deadtimes are wrong and therefore adding or removing fuel where it doesnt need to be.  

For the wall wetting I know it is disabled during start up so it is unlikely but I thought there could potentially be something triggering it either at shutdown or shortly after starting that causes the flooding.

 

 

 

[DerekAE86]

On 7/17/2023 at 3:06 PM, Adamw said:

If you add the SPWA figures on to that - at 0.5PW the SPWA is -0.066 and at 0.625PW the SPWA is +0.046 so you actually end up with a final PW of 0.434ms for the commanded 0.5 and final of 0.646 for the 0.6 commanded, or you could say 48% extra fuel/PW. 

Is it common for there to be SPWAs in negative values? Seems counter intuitive.

Also I see that Effective PW ms, Actual PW ms and Deadtime ms are are loggable parameters - but no SPWA ms?
I guess you could just create a mathblock to calculate it. Would be interesting to have a live read out of how much % extra fuel is being commanded due to DT and/or SPWA to see if there is any relation to AFR Target error/CLL Corr %.

[Vaughan]

34 minutes ago, DerekAE86 said:

Is it common for there to be SPWAs in negative values? Seems counter intuitive.

yes it is very common, sometimes the injector puts in too much fuel for the pulsewidth, other times too little. If too much fuel is being put in for the pulsewidth then a negative spwa is required to reduce the pulsewidth.

35 minutes ago, DerekAE86 said:

Also I see that Effective PW ms, Actual PW ms and Deadtime ms are are loggable parameters - but no SPWA ms?

spwa values are applied per injector and so aren't particularly easy to log and typically there is no requirement to log them as they are just correcting non linear behaviour of the injector at the very low pulsewidth end of their operation.

[Adamw]

5 hours ago, DerekAE86 said:

Is it common for there to be SPWAs in negative values? Seems counter intuitive.

Here's a visual that may help see how SPWA works.  

 

[maccakpa]

On 7/17/2023 at 1:06 PM, Adamw said:

I suspect the unstable idle is possibly due to the SPWA as the lambda bounces up and down by a whole lot more than the reported effective PW.  You can see his reported Eff PW is bouncing between about 0.5 and 0.6mS (this reported value doesnt include SPWA).  If the injector was perfectly linear then 0.6ms would be 20% more fuel than 0.5ms.  If you add the SPWA figures on to that - at 0.5PW the SPWA is -0.066 and at 0.625PW the SPWA is +0.046 so you actually end up with a final PW of 0.434ms for the commanded 0.5 and final of 0.646 for the 0.6 commanded, or you could say 48% extra fuel/PW.  Obviously those adders are there to compensate for an injector that is not perfectly linear, but perhaps those or the deadtimes are wrong and therefore adding or removing fuel where it doesnt need to be.  

For the wall wetting I know it is disabled during start up so it is unlikely but I thought there could potentially be something triggering it either at shutdown or shortly after starting that causes the flooding.

 

 

 

after i change wall wetting to zero flooding problem went away and even idle becomes natural. Thanks to you guys!
About SPWA is I just downloaded it from Injectordynamic site. but the tricky thing is they have 2 datas for id1700 injectors