which tables to correct dipping idle on decel?
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
Originally Posted by Ragtop 99
The first 7 cells stock are zero for a 1999. I've reduced the remaining cells for a 90mm FAST TB using the 48% factor. Therefore the next 5 cells are not zero, but about half of stock. Is that reduction causing a problem?
Originally Posted by WS6FirebirdTA00
car is fine in open loop, it is all due to fueling. messed with the throttle cracker to get the rpms nice comming to a stop. im sure i could decrease the decay to make it last longer but thats patching a problem that is there. the second i turn off closed loop the **** is perfect, no over or undershoot at all. so ill deal wiht it until i have an open loop tune 
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
Originally Posted by SmokingWS6
How healthy are the o2's? good o2's will make or break idle in my experience.
Originally Posted by WS6FirebirdTA00
they are brand spanking new denso corvette rears, i think im going back wiht stock ones as these are pieces of ****. actaully take LONGER to heat up, and oscillate much much slower than the stock ones, even with changing the proportional fuel to help out. they are pretty damn accurate though, when they are nice and hot i tune off them and when i put the WB on its pretty much dead on +/- 1%
From what I've read Denso's don't work. I'd stick with stock on Bosch 13111's.
TECH Enthusiast
Joined: Mar 2004
Posts: 647
Likes: 0
From: Australia
Originally Posted by Ragtop 99
The first 7 cells stock are zero for a 1999. I've reduced the remaining cells for a 90mm FAST TB using the 48% factor. Therefore the next 5 cells are not zero, but about half of stock. Is that reduction causing a problem?
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
well i have messed with about anything you can, i cant really tell if the dip has gotten better in closed loop, i think i have to figure off the rich condition before i can fix it, and that doesnt want to go away with these injectors
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11 Second Club
Joined: Dec 2002
Posts: 1,498
Likes: 10
From: long island, ny
wel i have the same issue in my m6
but mine only happens if i bog it down to below 1000 when in gear and then push the clutch in
but mine does not raise up untill i hit the gas and it stumbles a lil bit
but mine only happens if i bog it down to below 1000 when in gear and then push the clutch in
but mine does not raise up untill i hit the gas and it stumbles a lil bit
Originally Posted by Ragtop 99
The first 7 cells stock are zero for a 1999. I've reduced the remaining cells for a 90mm FAST TB using the 48% factor. Therefore the next 5 cells are not zero, but about half of stock. Is that reduction causing a problem?
I don't know why nobody can figure this out, but an f-body pcm doesn't care how big your throttlebody blade is because it doesn't control the throttlebody angle. It probably is causing a problem, possibly not, but you definately changed it for all the wrong reasons.
Originally Posted by P Mack
48% factor!?!?! Holy ****, I must have posted 10 times in that thread that it's only for drive by wire throttle bodies.
How did you calculate 48% again?
You don't need it since you don't have an electronic throttlebody.
https://ls1tech.com/forums/pcm-diagnostics-tuning/335186-update-90mm-tb-48-effective-table.html
Maybe there are other threads with it where you posted that. In any case, anyone reading this will not make the same mistake.
My bad, i've probably replied to a couple different threads on the subject so i shouldn't expect you to know that. I see now that i only replied once in the original thread. Sorry for the bitchslap
Last edited by P Mack; Dec 2, 2005 at 01:55 PM.
Staging Lane
Joined: Aug 2003
Posts: 89
Likes: 0
From: S.A. TX
I have the same problem, not so much anymore. For me it was the effective area table being off. I tried messing with cracker and follower with little success. I built mine by logging commanded iac airflow and actual maf airflow and tweaked it till both were pretty much identical at all counts.
Now for the most part in a CL maf tune it comes down to idle real nice with ac on or off in cold or hot weather.
The only problem I have is sometimes driving slow with alot of clutch in/out, throttle on/off action it will stumble, and the friggin reverse stumble.
Now for the most part in a CL maf tune it comes down to idle real nice with ac on or off in cold or hot weather.
The only problem I have is sometimes driving slow with alot of clutch in/out, throttle on/off action it will stumble, and the friggin reverse stumble.
Originally Posted by MNR-0
Decel. is all follower. Cracker opens the IAC motor on accel. and maintains airflow at cruise. Everything, though, based around the Base Running Airflow table. You always start there - solves 90% of all problems.
If you have zeroed out the first dozen IAC cells in the "IAC vs Effective Area" table then its slewing your follower control, hence dropping right down. Whats recovering for you is the Stall Saver.
I would set the cracker and IAC tables back to stock and work from there.
If you have zeroed out the first dozen IAC cells in the "IAC vs Effective Area" table then its slewing your follower control, hence dropping right down. Whats recovering for you is the Stall Saver.
I would set the cracker and IAC tables back to stock and work from there.
I've been tuning my idle for a few months now, and still have similar problems to what he's describing. Idle will go down, then back up to 1200, then sit there or around 1000 till I stop.
It changes depending on my RAF numbers. IAC vs. EFFECTIVE is dialed in since the dynamic and actual airflow numbers cross. My IAC counts are 45-50 when warm.
I've been through probably 30 idle tunes so far.
