Evo 6 jerky coming off throttle

[evoleo]

Hi,

I recently finished, more or less, my project car which is a Mitsubishi Lancer Evo 6 RS2 LHD RalliArt Germany car running Link G4+ PnP which I had dyno tuned.

There are one or two issues remaining, which may or may not be related to each other.

1) Car drives fine and pulls good in all degrees of throttle application, say between 5% and 100% throttle. But, when I come completely off the throttle the car bucks about 3 times before settling. Same if I am off throttle and then come back on. This is present in every gear, but less so the higher gear/speed I go, and less so the more RPM and boost I have. The issue shows itself mostly during normal cruising, say 3000 RPM on highway when you may come off throttle completely, or just driving slowly on the parking lot in 2000 RPM and coming off and on the pedal. Idle is smooth, and driving with low throttle is also fairly smooth, it´s really just between foot off throttle and on throttle that the car bucks and really gets upset.

2) If I turn on AC right after a cold start the RPMs start going up and down rhythmically, and the light in the dash dims a bit. Does not seem to be an issue on a warm engine. I had a few cases earlier where the car could idle for a minute or two and completely die if AC was on, and only way to get it to come alive again would be to disconnect and connect the battery (ignition would be dead). 

I´ve attached a short 3 minute log which consists of a cold start, AC on, let it sit for a little while, AC off, drive around the block in 1st gear only and coming off throttle a few times to upset the car and cause the bucking I described. I tried letting go off the throttle at around 2000 RPM and stepping on the throttle at 1000 RPM. Map is also attached, and car specs are listed below.

Log. I come off the throttle at 1:34 mark, and come on again on 1:38 mark. You can clearly see the oscillations in RPM. I repeat this a few times.

https://drive.google.com/open?id=1Ju_bq65yHYHtwwEPhWdJTJ8MG9N0nvmk

Map:

https://drive.google.com/open?id=1sfwKny12obN8jJ-UGZlbTIUMUFFXWaQS

Accidentally mapped with fuel pressure regulator with no boost cable connected, hence high fuel pump duty cycle. Connected back on, but made no difference as far as the bucking goes.

Screenshot of behavior:

https://drive.google.com/open?id=1t5s1vbGpmutQdOnJtlzInRW1AmF-yEpD

Car specs:

Forged 2.0 L

Balance shaft delete

Standard cams

Evo 9 series 80 Turbo with Turbosmart 18 psi actuator

Injector dynamics 1050x

New iridium plugs

COP kit

60 mm intercooler piping

Stock recirculating diverter valve setup (tried both OEM and GFB)

HKS elbow, DP, decat and cat back

New Exedy Hyper Twin SD clutch

Factory new RS diff

Overhauled transfer box with new CwP, backlash adjusted

60000 km on car and it was butter smooth before a rod went pop and I had to do an engine, and decided to upgrade the engine, clutch and ECU.

[evoleo]

Bump, any suggestions?

[evoleo]

Bump again, any suggestions?

 

Thanks!

[cj]

As a starting point set a speed threshold on your idle ignition timing (maybe around 10kph). Also drop the rpm threshold for this to somewhere around 1500. Whats happening right now is that as soon as you get off the gas pedal ignition idle turns on and immediately pulls all your ignition timing.

There are probably a bunch more contributing factors I havent had time to check yet. Do you have a lambda sensor installed? its showing 0 the whole log. Also, can you please include injector effective pulse width as a logged parameter & fuel table 1 value? Or better yet set it to log all values if its a PC log.

[evoleo]

44 minutes ago, cj said:

As a starting point set a speed threshold on your idle ignition timing (maybe around 10kph). Also drop the rpm threshold for this to somewhere around 1500. Whats happening right now is that as soon as you get off the gas pedal ignition idle turns on and immediately pulls all your ignition timing.

There are probably a bunch more contributing factors I havent had time to check yet. Do you have a lambda sensor installed? its showing 0 the whole log. Also, can you please include injector effective pulse width as a logged parameter & fuel table 1 value? Or better yet set it to log all values if its a PC log.

Hi, thanks a lot for replying, really appreciate it 

Early flight in the morning and it´s midnight here, so I´ll test the idle ignition timing when I am back on Thursday.

Standard lambda is installed in the elbow, but no wideband. If faulty it should have given me a CE light in the dash? I did not map myself, so I will have to ask the tuner, and do some investigating myself. Edit: Closed loop lambda is set to off... Is that the culprit?

Managed to get a quick drive in using add all in logs. Driving in 1st gear, holding 2000 RPM, releasing throttle pedal, getting back on it around 1000 RPM. A few times like that around the block.

https://drive.google.com/open?id=1t-RgozbopC3VBUyW8Ukxjng8BSdP7WII

[cj]

Narrowband lambda sensors are borderline useless for tuning - they just show rich or lean, but not a usable number. Interestingly yours reads lean for that entire log which is possible given you dont see any boost, but its a bit unlikely. A wideband sensor would make any tuning (outside of a dyno with its own sensors) a lot easier. 

What fuel pressure was this tuned at? The dead times used are for 45psi, and you are running very small pulse widths so this will have a big impact on low throttle/idle performance. You also dont have any short pulse adders configured, which will also really help given the low pulse widths.

try putting in the 1050x data from here http://help.injectordynamics.com/support/solutions/articles/4000074340-link-engine-management

[Leiden]

+1 for what CJ said

I try to do most of my idle ignition timing with the main ignition table, or at least have the idle ignition timing table somewhat close to what's in the main ignition table. Large jumps in timing can create the bucking/jerking you mentioned.

If your looking for off idle throttle response you can set the cells above your normal idle vacuum cells higher than your idle ones, this also helps to create a smooth transition in timing. See the attached file for an example, I smoothed the timing a bit in the idle, cruise areas

Leonid_smoothed.pclr

[evoleo]

Hi guys, thanks for the feedback!

Tried to load the map Leiden provided, but no noticeable difference. Also tried to add the the short pulse adders, and adjust the idle ignition settings as instructed, but still no noticeable difference when it comes to the bucking.

If the assumption that the car is going to idle as soon as I get off the pedal is correct, could it be the MAP and TP/AP Lockout settings need to be fine tuned? TP/AP lockout is at 1%, while actual TPS off the pedal is 0,6%. I see that the MAP lockout is at 55 kPa, but in the instances where I drive in 1st gear slowly holding 2000 RPM the MAP is 42 kPa, then I get off the gas, and bucking happens and MAP reading drops to 29 kPa when totally off the pedal.

[Adamw]

As well as the changes that Leiden made, I would also suggest you make the changes in red below.  This will prevent idle ignition kicking in while you are still driving.

[Leiden]

Calibrate your TPS so that off throttle is 0%, full throttle is 100%

Is there any reason you are using Idle Ignition timing control? I see that you have a Idle Stepper Motor enabled on the Aux 5 - 8 outputs, if your unable to bring the idle down enough you might need to have a look at adjusting the throttle stop screw (to reduce bypass airflow) or adjust the idle bypass screw (if the vehicle has one).

Can you do an up to date log with the changes you have made so far

[evoleo]

Leiden, are you talking about calibrating the actual sensor, not just TPS calibration? Reads 0,67V when off pedal, seems to be a normal value from what others have posted about their Evos.

Not sure why Idle Ignition Timing Control is on, I am not the tuner, just the owner of the car. I tried to turn it off, made no difference. The car idles very stable regardless.

Here is a log with your map with short pulse adders set, and changes to the idle ignition timing and speed sensor, as suggested. Did not really change anything as far as the experienced bucking coming on/off throttle goes, but here´s the log of the testing on a parking lot:

https://drive.google.com/open?id=1AaFhcXceKJeuZMEZOPy04hRg_Lpk3GoA

By the way, when dowloading "ID1050x - Link Characterization Tables - 8-24-17.xls" from the provided link to a Windows computer the antivirus detects a trojan, I´ve let ID know by e-mail

[Leiden]

I'm talking about calibrating it in the Link software so that its reading 0% closed. You can see from the log files that when you are off throttle you are reading 0.6%, this can cause some issues with TP lockouts which are often in the 0.2 - 1% range. Go to the ECU Controls menu and select TPS Setup then follow the instructions, its pretty simple.

I can see from your logs that the timing is jumping around a little when you come off throttle but I don't think this is your main issue, I see that the pulse widths are quite low and you haven't got a Min Effective Pulse Width set in Fuel Main, also in your main fuel table there is a bit of a dip right in this area.

The reason I asked for the most recent tune file is so I can cross reference the log file to the settings, I'm currently using the smoothed one I uploaded but if some other changes have been made its a bit hard to pin point it without the most recent file. I suspect the -70, -80, and -100 areas of the fuel map are a little on the low side.

Calibrate your TPS and try setting your Min Effective Pulse Width to something like 0.650ms and see if that makes any difference

Edit: I thought I should mention jerkiness can also be caused by worn driveline components, for instance a worn out dual mass flywheel, C.V shafts, gearbox, etc. One way to tell is to put your car in gear and rock it forward and back, if there is a lot of movement before you feel the engine loading up then this may well be your issue

 

[evoleo]

On 10/5/2019 at 11:30 PM, Adamw said:

As well as the changes that Leiden made, I would also suggest you make the changes in red below.  This will prevent idle ignition kicking in while you are still driving.

So, I think I figured out why I have not not experienced any noticeable changes when playing around with the idle ignition control. My car is an RS, hence no ABS and no wheel speed sensors. I see that DI#4 is set as LF Wheel Speed. Is there any way to use the speedometer sensor in the gearbox as the source for wheel speed? Or do I just have to try out all of the options and see? Will have hands on the car tomorrow.

On 10/9/2019 at 1:57 PM, Leiden said:

I'm talking about calibrating it in the Link software so that its reading 0% closed. You can see from the log files that when you are off throttle you are reading 0.6%, this can cause some issues with TP lockouts which are often in the 0.2 - 1% range. Go to the ECU Controls menu and select TPS Setup then follow the instructions, its pretty simple.

I can see from your logs that the timing is jumping around a little when you come off throttle but I don't think this is your main issue, I see that the pulse widths are quite low and you haven't got a Min Effective Pulse Width set in Fuel Main, also in your main fuel table there is a bit of a dip right in this area.

The reason I asked for the most recent tune file is so I can cross reference the log file to the settings, I'm currently using the smoothed one I uploaded but if some other changes have been made its a bit hard to pin point it without the most recent file. I suspect the -70, -80, and -100 areas of the fuel map are a little on the low side.

Calibrate your TPS and try setting your Min Effective Pulse Width to something like 0.650ms and see if that makes any difference

Edit: I thought I should mention jerkiness can also be caused by worn driveline components, for instance a worn out dual mass flywheel, C.V shafts, gearbox, etc. One way to tell is to put your car in gear and rock it forward and back, if there is a lot of movement before you feel the engine loading up then this may well be your issue

 

I ran the automatic TPS Setup from ECU controls several times and closed throttle always ends up at 0.67V. Seems this is the common value for Evos, after a bit of searching. 

Will attempt setting the Min Effective Pulse Width to 0.650, and upload new logs using your map. As above, I think all the changes done with Idle Ignition Control have been without effect due to the wheel speed issue. 

Drivetrain is basically new on the car, but I will double check CV shafts, although they are low mileage as well.

 

Thanks a lot guys, really appreciate it

[Adamw]

13 hours ago, evoleo said:

I see that DI#4 is set as LF Wheel Speed. Is there any way to use the speedometer sensor in the gearbox as the source for wheel speed? Or do I just have to try out all of the options and see? Will have hands on the car tomorrow.

DI4 is the gearbox sensor, it is just set to LF wheel speed as many functions need a driven wheel speed assigned to work properly.

So your speed lockout for idle ignition control should be working fine.  Just check in the speed sources menu that both driven and non driven wheel speed is set to LF.

 

13 hours ago, evoleo said:

I ran the automatic TPS Setup from ECU controls several times and closed throttle always ends up at 0.67V.

He was talkng about "0%", not 0V.

[Omgevo]

Hi,

ive Got a evo 5 and I’ve got the same issue, just wanting to know if you were able to fix the bucking issue?

 

cheers 

[MichaelR32GTR]

Does RPM lockout change if running electronic throttle ?

[Adamw]

14 minutes ago, MichaelR32GTR said:

Does RPM lockout change if running electronic throttle ?

What do you mean?  Why would RPM behave different for E-throttle?

[MichaelR32GTR]

Sorry what I meant was I just checked mine it’s set at 150rpm, the pop up help section said 150rpm should be used when running electronic throttle

 

i also have the same issue as this guy

i might try up the rpm lockout and see 

[Adamw]

Will need to see a log, but unlikely the RPM lockout is your issue.  400RPM seems to work pretty well for all the E-throttle cars I drive.  

[MichaelR32GTR]

7 hours ago, Adamw said:

What do you mean?  Why would RPM behave different for E-throttle?

Sorry just checked my settings again:

MAP lockout is 100kpa

RPM lockout is 2000rpm

Speed lockout is 20kmh

tp/ap lockout is 4.0%

 

do these settings seem abit high and could be giving me issues at at slow speed/light load like in car parks etc ?

[Adamw]

Yes, having RPM and TP lockout too high usually results in the ECU assuming you are trying to idle when you are cruising slowly or in over-run conditions slowing down, so it closes the throttle trying to bring the RPM down to your target.  Then as soon as you push in the clutch it will stall as the throttle is too far closed. 

RPM lockout around 400 usually works ok, TP lockout 0.5%, MAP lockout set 20kpa above your normal idle vacuum (check both warm and cold), speed lockout depends a lot on how the driver drives.  Some guys always push in the clutch or engage neutral when rolling up to lights etc - they need a higher lockout than someone for instance that leaves the clutch engaged all the way until car is nearly stopped. 

[Omgevo]

Hi Adamw, is there any way to fix this issue for a evo with a throttle cable?

Thanks 

[Adamw]

It would be best to attach a log from your car showing the issue along with your tune file.