cruise effect and high idle
10-13-2005, 07:56 AM
#1
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cruise effect and high idle I havent had alot of time to mess with tuning quircks recently.
Ive got a problem with high idle when I let off the accelerator it will stay around 1500-1800 rpms while moving slow.
It also tends to over rev when going into drive from any other gear. Drives itself when going under 40 mph.
Also the converter will unlock when I let off the accelerator completely.
Ive got a problem with high idle when I let off the accelerator it will stay around 1500-1800 rpms while moving slow.
It also tends to over rev when going into drive from any other gear. Drives itself when going under 40 mph.
Also the converter will unlock when I let off the accelerator completely.
10-13-2005, 05:03 PM
#2
Most likely your IAC Effective Area table needs adjusting. What kind of tuning software do you have?
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
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10-13-2005, 05:14 PM
#3
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Originally Posted by Patrick G
Most likely your IAC Effective Area table needs adjusting. What kind of tuning software do you have?
10-13-2005, 05:37 PM
#4
I found that my idle and all-around driving pleasure increased after I adjusted the IAC effective area and put the Throttle Cracker and Throttle follower tables back to stock. The IAC Effective Area is probably the most critical and misunderstood tables in LS1 tuning. Tweaking it correctly will make your life a lot happier.
10-13-2005, 06:24 PM
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On the IAC effective area table, I read some write-ups to adjust the table x amount to the right. What does this mean exactly? They first few cells are all 0's, does this mean extend the zeros more cells to the right?
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10-13-2005, 09:46 PM
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same here, cruise effect and high idle, I tried to tune the idle but I didn't really fool with the throttle cracker table and the IAC effective area. Is there a good method on how to adjust these tables??
10-13-2005, 11:15 PM
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Yes, my understanding what I have done...
Highlight the IAC Eff Table, I start with three 0's before the numbers, right click and copy, then paste it where the first number was. Basically shifting the table to the right, so that where the 1st three numbers other than 0 were, there are now 0's and all the numbers just slide to the right some. Dont worry about the numbers dropping off the far right of the table. Not sure if there is a cheater spreadsheet to figure out the exact amount to shift, or if its better to multiple the table by x, but shifting works. GL
Charlie
Highlight the IAC Eff Table, I start with three 0's before the numbers, right click and copy, then paste it where the first number was. Basically shifting the table to the right, so that where the 1st three numbers other than 0 were, there are now 0's and all the numbers just slide to the right some. Dont worry about the numbers dropping off the far right of the table. Not sure if there is a cheater spreadsheet to figure out the exact amount to shift, or if its better to multiple the table by x, but shifting works. GL
Charlie
10-14-2005, 06:36 AM
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ok I'm still trying to find the table 
I went the airlfow section and I can't find IAC effective table, I'm using HP Tuner's also, but I have the first version, was this an new table on the updated version?
I went the airlfow section and I can't find IAC effective table, I'm using HP Tuner's also, but I have the first version, was this an new table on the updated version? Last edited by Hardtop00SS; 10-14-2005 at 06:53 AM.
10-14-2005, 06:55 AM
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also is there a reason this would start to happen all of a sudden?? I mean my car was running fine until I ran a 1/4 mile pass and it haven't been right since, checked all the obvious, but I narrowed it down to the tune...
10-14-2005, 09:37 AM
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I have increased the iac table alot and set other idle air back to stock except for the base air table. This helped but I still have problems with braking and wheel turned all the way over especially in reverse at low speeds.
What should I be logging and looking for?
It seems like it should be possible to just tune out these problems with the base air, iat tables and throttle cracker without having to adjust the throttle set screw, this is what Ive been trying to do.
What should I be logging and looking for?
It seems like it should be possible to just tune out these problems with the base air, iat tables and throttle cracker without having to adjust the throttle set screw, this is what Ive been trying to do.
10-18-2005, 08:06 AM
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Originally Posted by 02sierraz71_5.3
I have increased the iac table alot and set other idle air back to stock except for the base air table. This helped but I still have problems with braking and wheel turned all the way over especially in reverse at low speeds.
What should I be logging and looking for?
It seems like it should be possible to just tune out these problems with the base air, iat tables and throttle cracker without having to adjust the throttle set screw, this is what Ive been trying to do.
What should I be logging and looking for?
It seems like it should be possible to just tune out these problems with the base air, iat tables and throttle cracker without having to adjust the throttle set screw, this is what Ive been trying to do.
10-18-2005, 12:19 PM
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Originally Posted by P Mack
If your idle trims are always near zero and you still get stalling, try using the spark to catch it. I doubled my spark underspeed values and it helped.
Ive shifted the iac area table to the right 5 spots and reduced it by 5% also reduced the base airflow table to around 10 when up to temp. Found that the more you increase the base airflow the higher your iac count. Ive got the stit under .20 and dynamic vs desired air within .2 difference but I cant seem to get my iac below 50 it jumps around from 53 to 63.
It tends to dip slightly and when parking it will surge going to around 350 rpms then surging to around 1300 it doesnt die but its a pain in the *** and I cant figure it out.
It seems the base airflow table can be offset by the iac table but Im wondering about the actuall values or ranges causing problems.
10-18-2005, 12:32 PM
#18
If your IACs are running above 50 and the tuning is pretty close, I would adjust your idle set screw to open the TB blade a bit. A hot IAC count of 40 - 44 would be a good target.
Is your VE pretty close at idle MAP/RPM? If you are too rich, that pushed the MAP up and you get into a nasty cycle.
Is your VE pretty close at idle MAP/RPM? If you are too rich, that pushed the MAP up and you get into a nasty cycle.
10-19-2005, 08:49 AM
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Originally Posted by Ragtop 99
If your IACs are running above 50 and the tuning is pretty close, I would adjust your idle set screw to open the TB blade a bit. A hot IAC count of 40 - 44 would be a good target.
Is your VE pretty close at idle MAP/RPM? If you are too rich, that pushed the MAP up and you get into a nasty cycle.
Is your VE pretty close at idle MAP/RPM? If you are too rich, that pushed the MAP up and you get into a nasty cycle.
Just out of curiosity how much do you guys adjust you throttle set screw for a cam in the 228 range?
