When accelarating and decelerating
06-05-2011, 10:39 AM
#1
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When accelarating and decelerating
Hi Guys
Maybe you can help me out on this issue .
I have a K-pro installed in my car and everything works perfect , the only issue i have is this :
After the car has been tuned i ve noticed that when cruising at low rpm like kind of 2000rpm on second and third gear when i lift my foot from the throttle and re apply the throttle very slowly the car just gives a harsh engagement to the transmission and the diff.
I' m not quite sure if i am explaining my self right !! it s like when you have a faulty engine mount .
Also i ve noticed that when i m at around 2000rpm -3000rpm and lifting of the throttle completely , the car just goes for a split of a second forward , it s like i have applied again partially the throttle.
By the way my car is equipped with 650cc injectors as my motor is modified .
Please let me now if you can help me out .
Nicky
Maybe you can help me out on this issue .
I have a K-pro installed in my car and everything works perfect , the only issue i have is this :
After the car has been tuned i ve noticed that when cruising at low rpm like kind of 2000rpm on second and third gear when i lift my foot from the throttle and re apply the throttle very slowly the car just gives a harsh engagement to the transmission and the diff.
I' m not quite sure if i am explaining my self right !! it s like when you have a faulty engine mount .
Also i ve noticed that when i m at around 2000rpm -3000rpm and lifting of the throttle completely , the car just goes for a split of a second forward , it s like i have applied again partially the throttle.
By the way my car is equipped with 650cc injectors as my motor is modified .
Please let me now if you can help me out .
Nicky
06-05-2011, 10:52 AM
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Hi .
To tell you the truth i won t say that the problem is from the tuning cause A/F ratios are very good and even timing .
I was thinking that maybe there is a setting or something when applying and letting go throttle at very low RPM.
This is the only issue i have . When i m cruising.
Nicky
To tell you the truth i won t say that the problem is from the tuning cause A/F ratios are very good and even timing .
I was thinking that maybe there is a setting or something when applying and letting go throttle at very low RPM.
This is the only issue i have . When i m cruising.
Nicky
06-05-2011, 10:55 AM
#4
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Well the tuner is the one who should make sure all settings are correct, hence me saying its a tune issue.
I know there is tip in, but not sure if that is for the scenario you described.
Also situations like you described are where good injectors shine as opposed to old technology injectors.
I know there is tip in, but not sure if that is for the scenario you described.
Also situations like you described are where good injectors shine as opposed to old technology injectors.
06-05-2011, 12:41 PM
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Well the tuner is the one who should make sure all settings are correct, hence me saying its a tune issue.
I know there is tip in, but not sure if that is for the scenario you described.
Also situations like you described are where good injectors shine as opposed to old technology injectors.
I know there is tip in, but not sure if that is for the scenario you described.
Also situations like you described are where good injectors shine as opposed to old technology injectors.
Yea it is a tune issue !!
In regarding the injectors they are the RC 650 which i have bought them around a year ago ! So i guess they should nt be a bad product (:
May i please ask what do you mean by (tip in ) ??
nicky.
06-06-2011, 10:28 AM
#7
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The issue you are describing is because the part-throttle fueling is slightly off, the jolt you feel is from the ECU applying a short term trim to correct the fueling.
You wont notice it watching the wideband gauge as the ECU applys the trim quicker than the sample rate of the gauge.
Dan
You wont notice it watching the wideband gauge as the ECU applys the trim quicker than the sample rate of the gauge.
Dan
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06-06-2011, 10:41 PM
#8
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"Tip in", is an enrichment for fast throttle input. The bigger the TB you run, the more air that is allowed in per TPS %. So if you put a big TB on and mash it to the floor, you'll actually run lean for a second until you mess with the "tip in"
06-07-2011, 05:05 AM
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Many thanks for the information
So the Tip in is the TPS SCALE right ?? as mine is setted at minimum 1% and max 104% . And I M RUNNING A STOCK TB.
Shall i change it to default ??
Thanks
Nicky
06-07-2011, 03:21 PM
#10
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I use FlashPro, but im sure the TPS SCALE will be the scaling for the throttle position sensor.
I'm pretty sure your issue is the part throttle fueling though, as when I was in the preliminary stages of tuning my part-throttle the very same condition would occur when the ECU had to make large changes to the short term trim. E.g. +-30%... When I had finished tuning part-throttle I never felt it again.
The reason why this may have happened is that:
There are targets set in the settings of KManager which determine what air-fuel ratio your wanting the ECU to aim for during part-throttle.. this is determined by load (manifold pressure) as to what the ECU will be trying to hit during these instances (usually this is 14.7AFR at low load, under a certain map pressure and around 13.5ish AFR at mid-load). Now your tuner may have been aiming for a differnt AFR during part-throttle tuning compared to what is listed in the targets, therefore the ECU will be adding trims to try and achieve the targets.
You only notice the jolt when you move the throttle very slowly because this is when the ECU has chance to apply trims based on what the reading is from the lambda sensor. during quick throttle movement the ECU is reading straight off the fuel tables..applying fewer and smaller trims.
During wide open throttle non of the above is relevant as the ECU is running in open-loop. fueling solely on what the fuel tables dictate.
Dan
I'm pretty sure your issue is the part throttle fueling though, as when I was in the preliminary stages of tuning my part-throttle the very same condition would occur when the ECU had to make large changes to the short term trim. E.g. +-30%... When I had finished tuning part-throttle I never felt it again.
The reason why this may have happened is that:
There are targets set in the settings of KManager which determine what air-fuel ratio your wanting the ECU to aim for during part-throttle.. this is determined by load (manifold pressure) as to what the ECU will be trying to hit during these instances (usually this is 14.7AFR at low load, under a certain map pressure and around 13.5ish AFR at mid-load). Now your tuner may have been aiming for a differnt AFR during part-throttle tuning compared to what is listed in the targets, therefore the ECU will be adding trims to try and achieve the targets.
You only notice the jolt when you move the throttle very slowly because this is when the ECU has chance to apply trims based on what the reading is from the lambda sensor. during quick throttle movement the ECU is reading straight off the fuel tables..applying fewer and smaller trims.
During wide open throttle non of the above is relevant as the ECU is running in open-loop. fueling solely on what the fuel tables dictate.
Dan