IAC counts 98 Vette

[ulllose]

I just got a-tap the other day,,did a quick log to try the software out. I had the car tuned last year,,,car runs great but idle alittle rough....(222/224 568 112lsa) so i decided to start messing with it. (i know the tuner didn't touch it other than bumping rpm up)and this guy has Tuned Mallets cars before:confused: Anyways i'm getting a 8-10 count at idle of 775-800rpm. load around 3%
I should be around 20-30 right??? And if thats the case,,buy letting more air in that drops the counts correct? So what do i have to do

thanks
ulllose
(98 C5-A4)

[JandJsTA]

You don't want to plug these numbers directly into your PCM but are a guide/suggestions for ruff idle heads/cam car :)


originally posted by NoGo on ls1tech.com



Here are some things you can try.



Idle Limiters --> Idle Speed: 950

Idle Limiters --> IAC Park Position: Raise all points from 40C and up to 21

Idle Limiters --> Idle Air In Gear: All points 60C and up to 8.6

Fuel --> Main VE Table: Multiply column 400 rpm by 60. Multiply column 800 by 80. Multiply column 1200 by 90.

Ignition --> High Octane Table: Add 2 deg to all points 400 to 1000 RPM, .08 to .32 g/sec



Once done with this program, start the car and check for surging. If the car surges, unplug the IAC and see if the surging stops. If the surging stops follow below.



Idle Limiters --> Idle Air in Gear --> All points above 60C to 9.2



Take the car for a drive and check your idle. If the car goes on cruise control reduce the Idle Air in Gear Table .2 (further if necessary). If the idle holds at 2000 RPM for extended periods of time reduce the P/N Airflow Decay table for all points above 10 MPH by 5% (multiply by 95) until this stops. Be vary careful on this table.



If car keeps surging with the IAC unplugged two more things to try.

Multiply Main VE table by another 95% (total reduction of 85%). Repeat until the surging goes away, or until the car begins to hesitate when you take off.

High Octane Ignition Table. Reduce timing for all points 400 to 1000 RPM, .08 to .32 g/sec by 2. Repeat, but don't reduce it any more than 6 degrees.





If your car still doesn't idle after this, then you have other problems, and should start looking elsewhere.

[ulllose]

ya i've seen this before,,,thanks
but the question still stands...."What IAC counts should i be at??
I seen peeple talking about this before,,,,,i've done a search but came up with nothing that made since. People are drilling the TB out to allow more air in past the IAC pin,,,,so i try posting again.

[JandJsTA]

In most discussions I have seen 20-30 seems to work best but I have actually never seen anyone wishing to raise the IAC at idle .. only the other way around :confused: , sorry I can't help ... you may also wish to look in the LS1edit email archives (http://www.ls1edit.com/pipermail/ls1edit/) and ask in the email forum http://www.ls1edit.com/ .... instructions on how to search the archives are in the FAQ thread at the top of this forum :)

[smiley]

http://smiley.tzo.com/fbody/atap/af.htm

IAC (idle) : 30-50
IAC (load) : <120

after adding my cam - my iac is a little low also. it like to hang around 25 so i'm not as bad as you. i also have been looking for a way to raise that number with no luck :(

[drptopz]

There is nothing wrong with counts around 20 - 25, this is what we normally shoot for.

[smiley]

ps - i always forget... my numbers are for fbody... not sure if the vette gets different iac counts or not.

[ulllose]

This hole IAc business is confusing the shit out of me......
I can seem to understand it. I hear people trying to keep IAC @20-30 around Idle and <120 with load. Any of my idle pim's don't do anything for me,,,i have one pim that measures the amount of air per/sec and the other measures counts but it never changes. I've read in the archives that other people have the same situation that i'm having (o counts) but i haven't read anything that corrects this or what to do if i have 0 counts blah blah blah. So the search goes on. Thanks guys for the replys though.

[drptopz]

If your truely getting counts of "0", either your throttle blades are open to much, or you have a vacuum leak someplace.

If your iac counts don't move when you give it throttle, something screwy is going on.

[EFILive]

Originally posted by ulllose
This hole IAc business is confusing the shit out of me......
I can seem to understand it. I hear people trying to keep IAC @20-30 around Idle and <120 with load. Any of my idle pim's don't do anything for me,,,i have one pim that measures the amount of air per/sec and the other measures counts but it never changes. I've read in the archives that other people have the same situation that i'm having (o counts) but i haven't read anything that corrects this or what to do if i have 0 counts blah blah blah. So the search goes on. Thanks guys for the replys though.

Ok, try this:

You have an AutoTap interface, you can download and install and run EFILive V5 free - using your AutoTap cable.
Select the following two IAC PIDs:
{GM.IAC}
{GM.IAC DES}
Start engine and let it idle
Then start logging.

You can only do this with EFILive V5 (not EFILive V6) because with an unregistered cable you can log about 5 seconds worth of data - that's enough to "see" the values of your IAC.
You can't log any data with an unregistered cable and EFILive V6.

I think you will see a different value than 0.

Regards
Paul

[ulllose]

paul----
Sounds like a good idea,,,,i just noticed you posted this. I'll try it tomorrow and i will post my findings.

Thanks again
Brian