Idle hunting and stumble returning to idle

[timslib]

G'day guys, 

Took my car out for a drive today and after it was all warmed up, it tended to stumble and stall when returning to idle, which is fairly standard. 

I'm trying to understand why it's doing that before taking it to my tuner, does anything stand out as obvious? 

Log and tune are attached, cheers.

idletune.pclr idle.llg

[stigc8]

I had a quick look, a few things I would change. Set your Idle control to closed loop and fix your idle ignition control, its going the wrong way, something like this.

 

 

[timslib]

1 minute ago, stigc8 said:

I had a quick look, a few things I would change. Set your Idle control to closed loop and fix your idle ignition control, its going the wrong way, something like this.

 

 

Roger that. Will do. 

[timslib]

4 hours ago, stigc8 said:

I had a quick look, a few things I would change. Set your Idle control to closed loop and fix your idle ignition control, its going the wrong way, something like this.

 

 

Hey mate, I just had another look at this map, and I'm not sure mines backwards. If you retard the timing as the idle is falling, you're moving away from MBT and the engine is making less torque, which won't speed it up. Conversely, if the idle is above target and it ignition is advancing, the engine speed should increase. 

[stigc8]

The left side of target error works when idle speed is too high, and right side is idle speed too low.

Middle is your ign timing with zero error, which is the number that your idle speed was setup to run with without closed loop enabled or ign idle control active.

[Adamw]

I agree that the idle ign table is back to front.  But the fuel set up looks wrong all over too - Its never going to idle well at 1.2lambda.

• The injector size is set to 980cc for fuel 1, it is set to 600cc for fuel 2.  They should flow less with ethanol but that looks like a pretty extreme difference.
• The idle VE is 22% in fuel table 1, it is 63% at the same point in fuel table 2. 
• The multi fuel density and temp coefficient appears to be set for E100 but the stoich ratio is set for about E85.
• The fuel pressure sensor calibration is wrong.  Fuel pressure also doesnt increase linearly with MGP, probably due to the same issue.
• The min effective PW is set to 0.99ms, this is unlikely correct and will prevent you from achieving the correct lambda when running petrol.  More typical value would be 0.2ms.
• The injector deadtime of 0.478ms at 14V is pretty unusual, not necessarily wrong but I would be doing some tests to confirm it is right.  
• Not related to the current issue, but the boost control solenoid on Ign 7 isn't going to work well unless you have fitted your own freewheeling diode.  If not I would suggest moving that to a proper aux output which has freewheeling built in. 

[stigc8]

1 minute ago, Adamw said:

I agree that the idle ign table is back to front.  But the fuel set up looks wrong all over too - Its never going to idle well at 1.2lambda.

• The injector size is set to 980cc for fuel 1, it is set to 600cc for fuel 2.  They should flow less with ethanol but that looks like a pretty extreme difference.
• The idle VE is 22% in fuel table 1, it is 63% at the same point in fuel table 2. 
• The multi fuel density and temp coefficient appears to be set for E100 but the stoich ratio is set for about E85.
• The fuel pressure sensor calibration is wrong.  Fuel pressure also doesnt increase linearly with MGP, probably due to the same issue.
• The min effective PW is set to 0.99ms, this is unlikely correct and will prevent you from achieving the correct lambda when running petrol.  More typical value would be 0.2ms.
• The injector deadtime of 0.478ms at 14V is pretty unusual, not necessarily wrong but I would be doing some tests to confirm it is right.  
• Not related to the current issue, but the boost control solenoid on Ign 7 isn't going to work well unless you have fitted your own freewheeling diode.  If not I would suggest moving that to a proper aux output which has freewheeling built in. 

I noticed most of this and plenty more, I dont think that map is the one off car, guessing its a tune used to show his idle settings only??

[timslib]

1 hour ago, stigc8 said:

The left side of target error works when idle speed is too high, and right side is idle speed too low.

Middle is your ign timing with zero error, which is the number that your idle speed was setup to run with without closed loop enabled or ign idle control active.

Ah roger, my thought process was back to front. Lol. Appreciate the insight there mate. 

31 minutes ago, Adamw said:

I agree that the idle ign table is back to front.  But the fuel set up looks wrong all over too - Its never going to idle well at 1.2lambda.

• The injector size is set to 980cc for fuel 1, it is set to 600cc for fuel 2.  They should flow less with ethanol but that looks like a pretty extreme difference.
• The idle VE is 22% in fuel table 1, it is 63% at the same point in fuel table 2. 
• The multi fuel density and temp coefficient appears to be set for E100 but the stoich ratio is set for about E85.
• The fuel pressure sensor calibration is wrong.  Fuel pressure also doesnt increase linearly with MGP, probably due to the same issue.
• The min effective PW is set to 0.99ms, this is unlikely correct and will prevent you from achieving the correct lambda when running petrol.  More typical value would be 0.2ms.
• The injector deadtime of 0.478ms at 14V is pretty unusual, not necessarily wrong but I would be doing some tests to confirm it is right.  
• Not related to the current issue, but the boost control solenoid on Ign 7 isn't going to work well unless you have fitted your own freewheeling diode.  If not I would suggest moving that to a proper aux output which has freewheeling built in. 

Roger that, time for a visit to the tuner. That's a big list. 

The car has been on the street 

34 minutes ago, Adamw said:

I agree that the idle ign table is back to front.  But the fuel set up looks wrong all over too - Its never going to idle well at 1.2lambda.

• The injector size is set to 980cc for fuel 1, it is set to 600cc for fuel 2.  They should flow less with ethanol but that looks like a pretty extreme difference.
• The idle VE is 22% in fuel table 1, it is 63% at the same point in fuel table 2. 
• The multi fuel density and temp coefficient appears to be set for E100 but the stoich ratio is set for about E85.
• The fuel pressure sensor calibration is wrong.  Fuel pressure also doesnt increase linearly with MGP, probably due to the same issue.
• The min effective PW is set to 0.99ms, this is unlikely correct and will prevent you from achieving the correct lambda when running petrol.  More typical value would be 0.2ms.
• The injector deadtime of 0.478ms at 14V is pretty unusual, not necessarily wrong but I would be doing some tests to confirm it is right.  
• Not related to the current issue, but the boost control solenoid on Ign 7 isn't going to work well unless you have fitted your own freewheeling diode.  If not I would suggest moving that to a proper aux output which has freewheeling built in. 

I'll go ahead and make changes to the boost solenoid wiring, minimum effective PW, and FP sensor calibration. Unlikely to improve everything much until the VE table and multi-fuel tables are setup right, then we'll go back to idle tuning. 

[timslib]

I'll also add that it has Bosch 985cc injectors, a Walbro 460 pump and Radium regulator, if anyone has accurate data for the injectors that I've not been able to find by Googling. 

[Adamw]

whats the injector part number

 

[timslib]

10 minutes ago, Adamw said:

whats the injector part number

 

I'll have to get a pic of one when I'm near the car. 

If this helps at all - these are the ones I bought. http://www.sonicperformance.com.au/BSS950/***SPECIAL***-Bosch-Fuel-Injector-980cc-3_or_4-Length/pd.php

[stigc8]

2 hours ago, timslib said:

I'll have to get a pic of one when I'm near the car. 

If this helps at all - these are the ones I bought. http://www.sonicperformance.com.au/BSS950/***SPECIAL***-Bosch-Fuel-Injector-980cc-3_or_4-Length/pd.php

 

[timslib]

7 minutes ago, stigc8 said:

 

Greatly appreciated mate, thank you!

[timslib]

On 4/15/2023 at 4:34 PM, Adamw said:

whats the injector part number

 

Hey Adam, just got home.

Bosch part number is 0 280 158 040. So they're just the generic 980s.

Cheers.

[Adamw]

My testing for the 040's using Link drivers:

Flow rate 892cc/min @ 300Kpa for petrol, I haven't tested this injector on ethanol yet.

 

[timslib]

Hello again gents, 

So, I went back today and added the data that @Adamw very graciously provided me, thank you kindly! I also made a new idle ignition table, which still needs a bit of tinkering with, but overall, it's idling a million times smoother. 

I also had a fiddle with the fuel table as I noticed it was idling MUCH (.6 Lambda) richer after adjusting the dead time and minimum PW, and it also seems to rev smoother now too. Idle seems to sit about .920Lambda at idle now.

Map/log attached for perusal. Thanks fellas.

idlelog2.0.llg idle2.0.pclr