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HELP! Doesn't return to idle in drive, "cruise control"

Old Aug 8, 2009 | 08:58 PM
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Default HELP! Doesn't return to idle in drive, "cruise control"

I tuned my bolt-ons and 224-112 cammed lq9 last week. It ran great all week. Tonite I'm cruisin down the road at 60, I let off to slow down, and the truck doesn't slow down! It stays at the same rpms and speed until I force it down with the brakes! It does this at slower speed (35 in town) too. I have the Base Running Airflow table dailed in and I adjusted the trottle follower and cracker tables. Any tips or advice? Please?
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Old Aug 8, 2009 | 09:09 PM
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the problem is in the throttle cracker
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Old Aug 8, 2009 | 09:15 PM
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And how do you suggest fixing it? I followed these steps by krambo:

Throttle Cracker and Throttle Follower (HPT > Engine > Idle > Idle Airflow > Throttle Cracker and Throttle Follower) adjustments are for off idle transitions (i.e. coming to a stop). As a guideline (since your standing idle is now fairly dialed in), zero out your cracker table from columns 400-1000rpm and through rows 0-32mph. Set the 1600rpm column from 0-12MPH to zero as well. Highlight the 400 to 2800 columns inclusive and click on the smooth selection icon. Again, smoothing is a good idea for proper transitions. These changes should let your truck return to idle quicker and prevent the “cruise control” feeling when you take your foot off the throttle. Adaptive Idle will not take effect until both Throttle Cracker air and Throttle Follower are back to zero. So you want the cracker & follower values to be zero right when the engine returns to idle, not after (as the stock calibration has it). The “Cruise Control” feeling is also a product of too much Base Running Airflow however since that table should now be dialed in, more than likely your Throttle Cracker Airflow table is to blame. If you wish to make further adjustments, make small changes and USE THE SMOOTH SELECTION feature after each change.

Throttle Follower parameters do not need too much adjustment IMHO. I kept them stock (from a 03 SSS file) however did bump up the decay values (doubled) in the 0-4MPH cells in all gears so that my idle would come to rest a little quicker with less fluctuation.

Last edited by 0235SS93; Aug 8, 2009 at 09:20 PM.
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Old Aug 8, 2009 | 09:19 PM
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Uhm..... reduce the throttle cracker in your tune. Also what're your throttle follower settings? Often times guys crank this up to keep the truck from stalling at a stop.
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Old Aug 8, 2009 | 09:25 PM
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I just doubled the decay values in columns 0-4 mph. By reduce the cracker, do you mean bigger or smaller values?
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Old Aug 9, 2009 | 07:02 AM
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cut the entire table in half. that will be a good start.
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Old Aug 9, 2009 | 02:55 PM
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I have the base running airflow dialed in. I've tweaked the throttle follower table, I set it back to stock. I took out 20-40% of the cracker table over and over and over again. No luck at all!If you come to stop and let off the brake, the truck will actually pull itself up to 25-30 mph! What else could it be???
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Old Aug 9, 2009 | 10:53 PM
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Here is my tune file as it is in the truck right now.
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Old Aug 9, 2009 | 11:56 PM
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Your base running airflow is too high.
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Old Aug 10, 2009 | 12:12 AM
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I've tried lowering it to near-stock levels, but no luck??? Maybe I'll try the stock table tommorrow. Are there any problems that could arise from the base running airflow table not being dialed? Will it hurt anything if I put the stock table in there?
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