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sensitive throttle response


don17

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my throttle response is really sensitive on deceleration, specially from 2000rpm to 1200ish. I get that jerking sensation on light throttle when trying to  depress the throttle lightly. also very sensitive on little throttle application around 2000/3000rpm, cruising speeds.  2JZGE-T NON VVTI , tune file attached. any help would be useful. I have re calibrated the TPS

new ignition boost 1800 2.pclr

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5 hours ago, 0x33 said:

can you post a log of it happening. also what throttle are you using

Will do later today, using a cable throttle body. Not electric 

4 hours ago, Øyvind Ryeng said:

When that condition happened to me recently it was caused by lean misfires. Adding a little fuel removed the issue completely.

Do you mean for crusing speeds or deceleration 

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A log would help, but the first thing I notice is you have quite a lot of advance in the coast/light cruise area, this is good from the point of view that it will be efficient and making good torque in this area, but it does have the consequence of making entry and exit of overrun fuel cut very fussy to get seamless as you have zero torque when fuel is cut and significant torque as soon as it is reinstated. 

I would start by reducing the overrun fuel cut TP threshold to 0.5%, increase the activation delay to 1.5s and the torque reduction/introduction to 1.5 or 2.0s.  Possibly increase retard to -15.  If that doesnt get it smoother you may have to pull a bit of timing out of the main table around the ORFC deactivation RPM also.  

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On 8/3/2023 at 9:18 PM, Adamw said:

A log would help, but the first thing I notice is you have quite a lot of advance in the coast/light cruise area, this is good from the point of view that it will be efficient and making good torque in this area, but it does have the consequence of making entry and exit of overrun fuel cut very fussy to get seamless as you have zero torque when fuel is cut and significant torque as soon as it is reinstated. 

I would start by reducing the overrun fuel cut TP threshold to 0.5%, increase the activation delay to 1.5s and the torque reduction/introduction to 1.5 or 2.0s.  Possibly increase retard to -15.  If that doesnt get it smoother you may have to pull a bit of timing out of the main table around the ORFC deactivation RPM also.  

This seemed to work perfectly, only issue I have remaining is the revs jumping around from  1800-1000 rmp when slowing down and slow speed like going through the car park, also I get a bit of a dip in rpm when taking off from a stopped position. 

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On 8/5/2023 at 4:24 PM, don17 said:

only issue I have remaining is the revs jumping around from  1800-1000 rmp when slowing down and slow speed like going through the car park

I think this is idle ignition kicking in and out since the speed lockout is 20kmh.  Drop it down to about 10kmh.  

 

On 8/5/2023 at 4:24 PM, don17 said:

also I get a bit of a dip in rpm when taking off from a stopped position. 

There is a dip at the beginning of the log but its hard to see what caused it.  The throttle and idle valve doesnt move.  Maybe you started to drag the clutch without touching the throttle?  Try the changes in green below so it doesnt disable idle ignition as soon as you start to load it. 

OAe2bLD.png 

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15 hours ago, Adamw said:

I think this is idle ignition kicking in and out since the speed lockout is 20kmh.  Drop it down to about 10kmh.  

 

There is a dip at the beginning of the log but its hard to see what caused it.  The throttle and idle valve doesnt move.  Maybe you started to drag the clutch without touching the throttle?  Try the changes in green below so it doesnt disable idle ignition as soon as you start to load it. 

OAe2bLD.png 

ill try these changes and see how it drives over the next week, thanks

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On 8/7/2023 at 7:57 PM, Adamw said:

I think this is idle ignition kicking in and out since the speed lockout is 20kmh.  Drop it down to about 10kmh.  

 

There is a dip at the beginning of the log but its hard to see what caused it.  The throttle and idle valve doesnt move.  Maybe you started to drag the clutch without touching the throttle?  Try the changes in green below so it doesnt disable idle ignition as soon as you start to load it. 

OAe2bLD.png 

The dropp at ideal is fixed, only thing remaining is the irratic deceleration around 1800-1100rpm, seems to get worse after those idle adjustments 

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