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Jenno007

Poor idle

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Hi guys,

I got my car tuned professionally and I will likely be taking it back to get some touch ups unless there someone here identifies a simple fix.

The car idles quite poorly, it constantly goes up and down from 900-1300rpm. Also on light throttle it struggles to rev (this is especially bad when cold on e85).

I've attached a log.

One thing to note, timing is all over the place AND something that I feel could be the culprit, the VVT is constantly turning on and off which seems to be causing this problem.

The log is from a cold start (20 degrees) on about e50.

If it's a more complex issue of fueling I will simply take it back to the tuner but hoping to save some time and $$.

Thanks

Log 2017-09-26 9;22;37 pm.llg

ecu26092017.pclr

I just unplugged the VVT and the car idles really badly, almost stalls. So I really think this has something to do with it.

Surely VVT shouldn't be turning on and off at idle?

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i far i can see from your map file the VVT control is OFF....so your mapper has wired in vvt solenoid in  auxiliary output 6 without using cam trigger...i guess the vvt now works as an ON/OFF mode and not as constantly variable timing as it sould be and it just change position from fully open to fully closed and vise versa...it can not get middle pisition as it sould be

The old bmw VANOS systems was ON/OFF...

in your case probable the problem here is that the vvt changes the camshaft timing too much degrees as i said it only gets 2 postions fully open or fully closed...maybe it changes 20 or more degrees and that cause your problems...

my advice is to use proper vvt configuration with camshaft postion sensor or KILL the vvt totaly and find a correct timing for your camshaft specs...i prefer the second method as its more simple and you can achive higher dynamic compression and great pulse tuning on the intake as the camshaft timing will be stable and always the same (as far the timings it make changes the pulse inside the intake will not be never be cordinate)

 

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i far i can see from your map file the VVT control is OFF....so your mapper has wired in vvt solenoid in  auxiliary output 6 without using cam trigger...i guess the vvt now works as an ON/OFF mode and not as constantly variable timing as it sould be and it just change position from fully open to fully closed and vise versa...it can not get middle pisition as it sould be

The old bmw VANOS systems was ON/OFF...

in your case probable the problem here is that the vvt changes the camshaft timing too much degrees as i said it only gets 2 postions fully open or fully closed...maybe it changes 20 or more degrees and that cause your problems...

my advice is to use proper vvt configuration with camshaft postion sensor or KILL the vvt totaly and find a correct timing for your camshaft specs...i prefer the second method as its more simple and you can achive higher dynamic compression and great pulse tuning on the intake as the camshaft timing will be stable and always the same (as far the timings it make changes the pulse inside the intake will not be never be cordinate)

 

Thank you for the reply!

Could you please advise how I go about this, is it as simple as turning off the VVT?

As far as I know, the VVT for my car only has two settings on and off, (car is Audi S3 8L).

Is it possible to make the VVT only kick in after a certain rpm? As I'm having no issues after say 2000rpm.

I hope this is the cause of the jerkyness I'm experiencing on light throttle.

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i am not 100% familiar with AUDI engines but from a little research i made its a truly VVT and not ON/OFF

if its a truly VVT then you need cam sensor in association with crank sensor to work it properly...If you try to work it as ON/OFF mode from an auxiliary port then you will have issues as you already have...also if you try to switch from 2000 rpm you will have problems because if you drive under 2000rpm then it will turned off and fully closed then if you try to drive a bit over 2000rpm it will be turned on and fully open this will make a feeling of "bouncing" and stalling because it needs some kind of hysteresis to work propery that aux output dont have...Hysteresis prevents outputs from switching rapidly on-off-on-off as the control signal hovers around the switching point

 

thats why your mapper as far i can see from your map it enables it at 1200rpm so its ON all the time from lets say idle until 5200rpm...as i already said you need to work it properly with cam sensor and vvt functions or just totaly KILL it and try to make a proper timing on your camshaft 

 

Edited by iceman_n

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As Iceman_n says, your VVT config looks a little odd considering the first couple google results suggest these engines have variable cams and not on/off. That being said, your idle fluctuations are not (entirely) caused by this. Only around 1 in 5 idle "cycles" is getting to a high enough RPM to have the cam switching kick in. The majority of your idle issues look to be related to how idle ignition timing is set up. Because your throttle opening at idle is set quite high at around 6%, the idle timing is set quite aggressively to attempt to pull your idle down to the 1100 its being asked for - ie instead of ~15deg at idle like a production car typically has, youre running about 5, and because there is so much air being allowed in by the throttle, when the idle control moves it from 5 to 7 degrees to try bring you idle up 100rpm or so, its overshooting and bumping it up by 300. Then the reverse happens, repeatedly.

You also have closed loop ethrottle control enabled which i've seen cause something similar when not correctly tuned, but it looks like the throttle position barely moves anyway.

To verify this is the problem, try changing closed loop idle ethrottle to open loop idle ethrottle and see if this helps. Next thing is to disable ignition idle control and check again. Expect your idle RPM to jump up quite a lot when doing this as 7% throttle at idle is quite a lot. If this stabilises the idle (but at too high a number), try lowering the numbers in your idle throttle % table until you get idle close to what you want. You may also need to lower the numbers in the top row of your ethrottle target if you get the idle numbers to 0 and its still idling too high.

Once you've got the idle about where you want it in open loop, try turning on closed loop and ignition idle again. You will probably need to adjust the idle ignition numbers a bit so that the 0 error column has roughly the same number as your main ignition table at idle. This may also help your just off idle response too. At the moment its having to jump ignition angle and throttle posistion quite a lot between where it idles and where it needs to be at light throttle

 

FYI this is mostly all in the help files under idle control. Have a read of that section.

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Based on this thread and your thread about boost control issues, I would assume that you need to take the car back to the tuner.

From my quick search, this should basically be the same motor as the audi tt with the 20v 1.8T motor.  If that is the case, then this is a simple on/off cam control.

And if the idle is fluctuating from 800-1300rpm then yes the cam will switch back and forth continuously.  The mapper has the cam switch whenever the rpm is between 1200 and 5200 rpm.

Edited by Brad Burnett

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As Iceman_n says, your VVT config looks a little odd considering the first couple google results suggest these engines have variable cams and not on/off. That being said, your idle fluctuations are not (entirely) caused by this. Only around 1 in 5 idle "cycles" is getting to a high enough RPM to have the cam switching kick in. The majority of your idle issues look to be related to how idle ignition timing is set up. Because your throttle opening at idle is set quite high at around 6%, the idle timing is set quite aggressively to attempt to pull your idle down to the 1100 its being asked for - ie instead of ~15deg at idle like a production car typically has, youre running about 5, and because there is so much air being allowed in by the throttle, when the idle control moves it from 5 to 7 degrees to try bring you idle up 100rpm or so, its overshooting and bumping it up by 300. Then the reverse happens, repeatedly.

You also have closed loop ethrottle control enabled which i've seen cause something similar when not correctly tuned, but it looks like the throttle position barely moves anyway.

To verify this is the problem, try changing closed loop idle ethrottle to open loop idle ethrottle and see if this helps. Next thing is to disable ignition idle control and check again. Expect your idle RPM to jump up quite a lot when doing this as 7% throttle at idle is quite a lot. If this stabilises the idle (but at too high a number), try lowering the numbers in your idle throttle % table until you get idle close to what you want. You may also need to lower the numbers in the top row of your ethrottle target if you get the idle numbers to 0 and its still idling too high.

Once you've got the idle about where you want it in open loop, try turning on closed loop and ignition idle again. You will probably need to adjust the idle ignition numbers a bit so that the 0 error column has roughly the same number as your main ignition table at idle. This may also help your just off idle response too. At the moment its having to jump ignition angle and throttle posistion quite a lot between where it idles and where it needs to be at light throttle

 

FYI this is mostly all in the help files under idle control. Have a read of that section.

Thank you for your help I will try this tonight!

Based on this thread and your thread about boost control issues, I would assume that you need to take the car back to the tuner.

From my quick search, this should basically be the same motor as the audi tt with the 20v 1.8T motor.  If that is the case, then this is a simple on/off cam control.

And if the idle is fluctuating from 800-1300rpm then yes the cam will switch back and forth continuously.  The mapper has the cam switch whenever the rpm is between 1200 and 5200 rpm.

I think I have resolved the boost control, it just required very high figures in the gear wastegate trim which I was unsure if that was normal. But I will take the car to the dyno sooner rather than later to make sure all AFRs and timing is correct.

This car has the exact same engine as the Audi TT. Given the previous response I will follow his instructions to see if I can get the idle smoother. I may also adjust the cam to switch at say 1500rpm to ensure this doesn't happen at idle, unless that will cause other sorts of problems?

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Seems like no-one so far is overly familiar with this motor so we cant advise you very well on when to use the VVT functions on this motor. Do you have a service manual or some sort of general description on when the factory ECU enables this and what its trying to achieve, or what it actually does to the cams/valves/etc? 

Even in the part of your log when your idle fluctuations only go between 800 and 1150 or so (and are below the cam switch RPM) the same fluctuations are visible, so changing the cam switch point up to 1500 will help rule it out, but I dont expect you will see much improvement in the idle from this.

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Seems like no-one so far is overly familiar with this motor so we cant advise you very well on when to use the VVT functions on this motor. Do you have a service manual or some sort of general description on when the factory ECU enables this and what its trying to achieve, or what it actually does to the cams/valves/etc? 

Even in the part of your log when your idle fluctuations only go between 800 and 1150 or so (and are below the cam switch RPM) the same fluctuations are visible, so changing the cam switch point up to 1500 will help rule it out, but I dont expect you will see much improvement in the idle from this.

I'm definitely going to try what you advised in your previous post as I feel this could be the culprit as I saw the timing jump all over the place during the idle.

Given when I unplugged the VVT it couldn't idle at all (just kept almost stalling), I feel that it plays some part, but I think if I increase the timing and decrease throttle as you advised it will help.

Should this fail I'll be taking it back to the tuner regardless but would like to try fix this myself if I can.

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As Iceman_n says, your VVT config looks a little odd considering the first couple google results suggest these engines have variable cams and not on/off. That being said, your idle fluctuations are not (entirely) caused by this. Only around 1 in 5 idle "cycles" is getting to a high enough RPM to have the cam switching kick in. The majority of your idle issues look to be related to how idle ignition timing is set up. Because your throttle opening at idle is set quite high at around 6%, the idle timing is set quite aggressively to attempt to pull your idle down to the 1100 its being asked for - ie instead of ~15deg at idle like a production car typically has, youre running about 5, and because there is so much air being allowed in by the throttle, when the idle control moves it from 5 to 7 degrees to try bring you idle up 100rpm or so, its overshooting and bumping it up by 300. Then the reverse happens, repeatedly.

You also have closed loop ethrottle control enabled which i've seen cause something similar when not correctly tuned, but it looks like the throttle position barely moves anyway.

To verify this is the problem, try changing closed loop idle ethrottle to open loop idle ethrottle and see if this helps. Next thing is to disable ignition idle control and check again. Expect your idle RPM to jump up quite a lot when doing this as 7% throttle at idle is quite a lot. If this stabilises the idle (but at too high a number), try lowering the numbers in your idle throttle % table until you get idle close to what you want. You may also need to lower the numbers in the top row of your ethrottle target if you get the idle numbers to 0 and its still idling too high.

Once you've got the idle about where you want it in open loop, try turning on closed loop and ignition idle again. You will probably need to adjust the idle ignition numbers a bit so that the 0 error column has roughly the same number as your main ignition table at idle. This may also help your just off idle response too. At the moment its having to jump ignition angle and throttle posistion quite a lot between where it idles and where it needs to be at light throttle

 

FYI this is mostly all in the help files under idle control. Have a read of that section.

I followed your advise and did the following:

Switched to open idle ethrottle and disabled ignition idle control. I didn't change anything else and attached is a log. It idles different, probably smoother but still jumps around a lot. It automatically adjusted the throttle body % and the timing seems more reasonable. Looking at my AFR gauge they did jump around a little. Strange that the ecu doesn't show me AFR, maybe I don't know where to look.

 

Any ideas as to why it's still jumping around a lot?

 

I really appreciate the help!

Log 2017-09-27 9;05;38 pm.llg

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i believe that the wrong vvt setup has major responsibility in idle because full advance on intake makes huge camshaft overlap...but cj has right too about the 6% open throttle is too much...

my opinion is : kill the vvt totaly..setup the car with nice smooth idle and goos cold start...then enable vvt again an try to fix it...it needs to be mapped well without the vvt as a good starting point some things must be FIXED to allow you to move on more proffesional things as vvt...

 

also as the vvt still remains on aux output it will not work properly...it needs to be moved on vvt output with camshaft sensor along side with crank sensor or to kill it permantly...thats your options

 

Edited by iceman_n

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The engine is a vw 1.8 20v motor.  It is not full variable VVT.  It is just on/off.

it not the same as the vw 1.8 20vt, vw has vvt only enabled on cold start for emission and some models without vvt this thread here is for audi s3...its different from vw engine but in general is the same engine....s3 has the same engine as seat ibiza cupra with 220hp and not 150 or 180 hp as vw

this came up from a little research i made but still not 100% sure, just saying....

Edited by iceman_n

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VW and Audi 1.8 T is the same. Go look at the link base cal for the Audi TT plugin

 

This car has the exact same engine as the Audi TT. Given the previous response I will follow his instructions to see if I can get the idle smoother. I may also adjust the cam to switch at say 1500rpm to ensure this doesn't happen at idle, unless that will cause other sorts of problems?

 

Edited by Brad Burnett

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I did some more digging on this engine and its VVT and Brad is right, it looks very on/off. Looks like mechanically the timing belt only drives the intake cam, and an actuator on the timing chain tensioner for the chain between the intake and exhaust cams allows it to push the chain to take a longer path and therefore phase one of the cams by about 15 degrees relative to the other one. It appears to only have up or down positions though and not able to move to any intermediate positions. 

http://forums.vwvortex.com/showthread.php?569755 see post #23 on this forum for a good explanation.

There also seems to be an agreement that its primarily there to create overlap at low RPM to increase torque/create an EGR like system, and should be on at low RPM's and off at high RPM's or once on boost but I wouldnt take my word for this.

@Jenno007 - your new log is definitely now suffering from VVT switching on and off repeatedly. It looks like the revs dont vary as much and your ignition numbers are now more stable, but there is still ~100rpm variance and at every single on of the cycles theres a cam switch event. You need to move that lower VVT switch threshold away from your idle range at least to start with. It doesnt matter if you make it 800rpm so its always on or 1800 so it doesnt kick in until you press the throttle, or disable it entirely for now, but it has to stop cycling on and off at idle range.

Your throttle is lower but is still 5% ish which is probably a little high, and your MAP values are 55-65. If you've got crazy big cams this might be normal but on most stock cams this would still suggest your throttle is open too much. I suspect once you disable/move VVT you'll find your idle at 1300 or so with the settings youve got.

[edit] - Also, you appear to have a narrow band O2 sensor and an LC1 configured in the ECU, but the value of both never changes so I suspect they arent wired up correctly. They arent at error value.but they never change, hence why you have no accurate lambda reading in the ecu

Edited by cj

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Your problem is most likely due to your injector pulse width being so short.  You only have 1.2-1.3ms in that last log so this will be in well into the non-linear region for most injectors.  If your injectors are from a reputable supplier then they should be able to provide "short pulse width adder" data to correct this.  If you cant get that data then your best option would be to lower fuel pressure so that pulsewidth can be increased.  That will mean a full re-tune however.

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I did some more digging on this engine and its VVT and Brad is right, it looks very on/off. Looks like mechanically the timing belt only drives the intake cam, and an actuator on the timing chain tensioner for the chain between the intake and exhaust cams allows it to push the chain to take a longer path and therefore phase one of the cams by about 15 degrees relative to the other one. It appears to only have up or down positions though and not able to move to any intermediate positions. 

http://forums.vwvortex.com/showthread.php?569755 see post #23 on this forum for a good explanation.

There also seems to be an agreement that its primarily there to create overlap at low RPM to increase torque/create an EGR like system, and should be on at low RPM's and off at high RPM's or once on boost but I wouldnt take my word for this.

@Jenno007 - your new log is definitely now suffering from VVT switching on and off repeatedly. It looks like the revs dont vary as much and your ignition numbers are now more stable, but there is still ~100rpm variance and at every single on of the cycles theres a cam switch event. You need to move that lower VVT switch threshold away from your idle range at least to start with. It doesnt matter if you make it 800rpm so its always on or 1800 so it doesnt kick in until you press the throttle, or disable it entirely for now, but it has to stop cycling on and off at idle range.

Your throttle is lower but is still 5% ish which is probably a little high, and your MAP values are 55-65. If you've got crazy big cams this might be normal but on most stock cams this would still suggest your throttle is open too much. I suspect once you disable/move VVT you'll find your idle at 1300 or so with the settings youve got.

[edit] - Also, you appear to have a narrow band O2 sensor and an LC1 configured in the ECU, but the value of both never changes so I suspect they arent wired up correctly. They arent at error value.but they never change, hence why you have no accurate lambda reading in the ecu

Little more background, the car has a wideband o2 sensor from factory, and a plug and play ecu. So I would have hoped the ecu knew it had a wideband o2 sensor. Not sure what an LC1 configured in the ECU means, I do have a wideband on my dash but it isn't wired into the ecu. The car does have reasonably aggressive cams. I will disable the VVT tonight and see how it goes. Given it will only take out a little bit of power up to approx 5500, I'm not overly concerned. If I simply disable the VVT, could this throw out the fueling & timing?

Given the amount invested in this car I'm going to call the tuner today and get them to fix it and do a full health check but I still like tinkering with it myself.

Your problem is most likely due to your injector pulse width being so short.  You only have 1.2-1.3ms in that last log so this will be in well into the non-linear region for most injectors.  If your injectors are from a reputable supplier then they should be able to provide "short pulse width adder" data to correct this.  If you cant get that data then your best option would be to lower fuel pressure so that pulsewidth can be increased.  That will mean a full re-tune however.

Hi Adam, the injectors are Injector Dynamic ID2000. They are a bit overkill but when I purchased them the ID1600 weren't available and ID1000 wouldn't be enough for the power I'm chasing on e85. At they time they assured me these would idle fine on a 2L 4cyl engine, especially on e85. So I'm hoping this isn't the problem!

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This is exactly your problem.

The good news is ID give you the data you need.  So use it!.

http://help.injectordynamics.com/support/solutions/articles/4000074340-link-engine-management

With cj's reply earlier, he seemed to think it was due to the VVT constantly turning on and off? Given this is a very simple fix I will turn off the VVT completely (or change it to activate at 2500 just to completely rule it out), and see if this fixes my problem.

The data means absolutely nothing to me, but I will give it to my tuner when I take the car back for a health check (and for him to fix the idle if I can't). Thanks for linking it.

I will try disabling the VVT first thing tonight and I'm really hopeful this fixes the problem. I'm slightly worried that the ECU isn't picking up the wideband so it cannot be making any fueling adjustments.

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The VVT is turning on and off repeatedly in your logs in line with the idle fluctuations so is probably at least part of the problems. I hadnt noticed your short pulse width adder table is all zero's though which is what adamw is talking about. On injectors that big Its probably contributing a fair bit to the problem as well. In fact the short pulse width adder table from ID has values up past the 0.6-0.8ms your seeing at idle, so not having that populated will be having an impact. Adding these in will only affect the idle and very light throttle parts of your tune so is a safe change to make.

All you have to do is copy the info from that spreadsheet into the short pulse adder table under fuel setup > injector setup

Interestingly, the values for the dead time table are not what is set in your tune. Changing these value will affect fuel quantity across your whole tune so you want to be a lot more careful changing these - less so at higher load but there is still some change everywhere. Ideally you would change your tune to use the deadtime tables provided by ID but if you're heading back to a tuner its probably worth getting them to do it and any fuel table changes to match, especially with an engine running that much boost.

LC1 is your Innovate wideband O2. Does it look like its reading correct numbers on the gauge? If so, i'd guess that the signal output wire (yellow or brown wire) is not hooked up properly to the link, or is connected to the wrong input. The LC1 default calibration is for 0.5 lambda at 0V output, which is exactly what your log is showing all the time so I suspect that input is either disconnected or is grounded instead of receiving signal from the LC1 controller.

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The VVT is turning on and off repeatedly in your logs in line with the idle fluctuations so is probably at least part of the problems. I hadnt noticed your short pulse width adder table is all zero's though which is what adamw is talking about. On injectors that big Its probably contributing a fair bit to the problem as well. In fact the short pulse width adder table from ID has values up past the 0.6-0.8ms your seeing at idle, so not having that populated will be having an impact. Adding these in will only affect the idle and very light throttle parts of your tune so is a safe change to make.

All you have to do is copy the info from that spreadsheet into the short pulse adder table under fuel setup > injector setup

Interestingly, the values for the dead time table are not what is set in your tune. Changing these value will affect fuel quantity across your whole tune so you want to be a lot more careful changing these - less so at higher load but there is still some change everywhere. Ideally you would change your tune to use the deadtime tables provided by ID but if you're heading back to a tuner its probably worth getting them to do it and any fuel table changes to match, especially with an engine running that much boost.

LC1 is your Innovate wideband O2. Does it look like its reading correct numbers on the gauge? If so, i'd guess that the signal output wire (yellow or brown wire) is not hooked up properly to the link, or is connected to the wrong input. The LC1 default calibration is for 0.5 lambda at 0V output, which is exactly what your log is showing all the time so I suspect that input is either disconnected or is grounded instead of receiving signal from the LC1 controller.

The difference in values could be due to the fact that I use a 3bar FPR and the table is for 4bar? I don't think I will play with these settings as it's probably best left for someone who knows what they are doing and I certainly do not haha. At least I can give the table to the tuner.

I'm not sure why there is a LG1 in the ecu as my innovate wideband O2 is not wired into the ECU at all and was never intended to be. The ecu has its separate O2 sensor which is the factory sensor. It's a shame that ECU isn't picking up this sensor, I will investigate that tonight.

The ECU is a plug in ecu, no additional wiring was done apart from a switch to change between high boost and low boost, the flex fuel sensor and the AIT sensor. All was done by the tuner. Given some cars which use this engine only have narrowband O2 sensors, maybe the ECU is setup to accommodate all models of the 20v 1.8t? I wonder if it is picking up the O2 sensor somewhere but just doesn't know what sensor it is?

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This is exactly your problem.

The good news is ID give you the data you need.  So use it!.

http://help.injectordynamics.com/support/solutions/articles/4000074340-link-engine-management

You sir are a genius.

I tried all of the changes you recommended CJ but unfortunately they didn't work, feeling defeated I put everything back to standard and made the changes to the injectors as Adamw recommended and the idle is near perfect!

Throttle response is so much better as well, before it was terrible but now it's great and the car drives so much better. I can't believe I have driven with the car the way I had it for over a year.

As you can see from the log the timing is still very low but the car idles much better. 

Any suggestions of other things to change? I am very happy with how the car idles now, but if anyone notices any glaring problems I'm all ears.

updated injectors.llg

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