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Question on making a correction in my tune..

 
Old 06-12-2019, 11:38 AM
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WW7
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Default Question on making a correction in my tune..

. The problem I'm having is , when I let off the gas pedal the rpms don't drop down like they're suppose to.. If I am driving along at any speed below around 30 mph and let off the gas , the rpm doesn't change and drop down and the car keeps pulling.. Which one of the tables in "Tuner Pro" would I address to get the rpms to drop down when the gas pedal is released...I know this problem is in the tune and not mechanical ,because when I disconnect the battery, then hook it back up , the rpms drop down like they're suppose to, once the ecm relearns , the problem is there again....WW

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Old 06-12-2019, 12:22 PM
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383vett
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Make sure the base throttle opening of your throttle body is not set too far open. Try turning the set screw down a turn or two and see what happens.
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Old 06-12-2019, 01:32 PM
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WW7
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Originally Posted by 383vett View Post
Make sure the base throttle opening of your throttle body is not set too far open. Try turning the set screw down a turn or two and see what happens.
Base idle has been set , I'm pretty sure this is a tuning problem...Thanks anyway...WW
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Old 06-12-2019, 02:13 PM
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Get a log of the event and note the behavior of the IAC, tps, vehicle speed, spark advance, injector pw, maf flow, load and rpm during the rpm hang condition. Would also be good to know the normal IAC counts in a warm stable idle in-gear. The IAC logic is complicated, so no simple answer without some data.
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Old 06-14-2019, 07:53 AM
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….. IAC "Hold" position ? …..
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Old 06-14-2019, 12:51 PM
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cardo0
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Originally Posted by WW7 View Post
. The problem I'm having is , when I let off the gas pedal the rpms don't drop down like they're suppose to.. If I am driving along at any speed below around 30 mph and let off the gas , the rpm doesn't change and drop down and the car keeps pulling.. Which one of the tables in "Tuner Pro" would I address to get the rpms to drop down when the gas pedal is released...I know this problem is in the tune and not mechanical ,because when I disconnect the battery, then hook it back up , the rpms drop down like they're suppose to, once the ecm relearns , the problem is there again....WW
I apologize I'm not familiar with Tuner Pro as I use TunerCats s/w. But there is a feature called Deceleration Fuel Cutoff DFCO which cuts fuel and lets the engine coast with the rpm's high and the throttle blades closed. You have to choose the rpm to start DFCO and a lower rpm to stop DFCO. That's something you will have to sort out yourself in Tuner Pro as an ECM won't have the car speed input as a PCM does.

Hope this can help.
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Old 06-14-2019, 02:58 PM
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Could be that the warm park position vs coolant temp is too high. Would be nice to see some data.

;------------------------------------------
; WARM PARK POSIT. vs COOLANT
;
;
; ARG = STEPS
;------------------------------------------
LC587: FCB 8 ; 8 + 1 LINES IN TABLE
;
; STEPS Deg c COOL
;------------------------------
LC588 FCB 125 ; 125 -40
LC589 FCB 100 ; 100 -16
LC58A FCB 75 ; 75 8
LC58B FCB 50 ; 50 32
LC58C FCB 25 ; 25 56
LC58D FCB 10 ; 10 80
LC58E FCB 5 ; 5 104
LC58F FCB 5 ; 5 128
LC590 FCB 5 ; 5 152
;------------------------------------------
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Old 06-14-2019, 03:07 PM
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WW7
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Thanks for the suggestions.. I will try to get out this weekend and do some datalogging... My son in law said he had the base idle set ' but I'm going to check it just to make sure he has it right... Thanks again. WW
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Old Yesterday, 09:41 AM
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In my ebl flash, its the "TF" OR Throttle follower settings.
I adjusted those settings making sure i got a quick snappy rev and the rpm would drop back down quickly for the next pedal tap.
It also ensures i get the maximum noise when using my engine to slow the car down.
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