Fast Idle Opinion With(with tune and scan)

[1slowbusa]

Hi,

Please see the attached tune and scan. Can you give me any opinions on how things look and if i need to do anything else that would complete my idle tuning for a fast 102 and NW 102 throttle body.

Thanks
The car is a 2000 camaro ss
g5x3 cam 112lsa
205 heads
1/7/8 headers
42 pound injectors

[WS6FirebirdTA00]

Looks like your idle is fluctuating quite a bit.

I would change the target idle speed table, it is not good IMO keeping it flat like that.

Idle trims are also not moving at all until it gets warmer, so your airflow table is probably off.

Idle spark tables are funky too. Don't just highlight an area and make it all flat. The benefit of HPT is you don't need to do global changes you can make curves. That high peak at 1600 bothers me too. Same goes for your standard spark tables, just not good practice.

Your VE table is also very screwy looking. I would address that. If that is off, your idle will be too.

May need to adjust your over and underspeed spark tables too.

[1slowbusa]

Can you explain the over and under spark tables so i can understand a little bit more.

Also since i am running a fast 102 and TB, do i need to adjust my ETC scalar down? How do i know how far to go?

I have the car in speed density mode so i just need to start the car and display my lambda_err_VE, vs Lambda Err. It seems that no matter what change i make in the primary and secondary VE tables (At the same time) the lambda that i read stays the same. Any opinion on this would be appriciated.

[WS6FirebirdTA00]

ETC scalar does not apply except when the car is fit with the ETC.

Make sure the car is in open loop when making changes, the o2s may be correcting back.

Over and under speed spark is a fast acting idle control. If the RPMs dip, timing goes up to help recovery. If the RPM flares timing is pulled to help get it under control. Sometimes if you rely too heavily on the IAC to control idle you will end up with a fluctuating idle.

[1slowbusa]

Over and under speed spark is a fast acting idle control. If the RPMs dip, timing goes up to help recovery. If the RPM flares timing is pulled to help get it under control. Sometimes if you rely too heavily on the IAC to control idle you will end up with a fluctuating idle.

This is exactly what i am doing. I am only trying to tune the base running Airflow and nothing else. Thanks

I am trying to follow the link below with regards to tuning the idle.

http://www.hptuners.com/forum/showth...+tuning+how-to

[WS6FirebirdTA00]

I disagree with a lot of what is stated in the thread to be honest with you.

[1slowbusa]

Do you have a writeup or a procedure that i can follow to get me started on the right track?

[MikeyZ]

looks like you possibly have a vacuum leak with you iac counts so hi

and if your aem gauge is accurate your not commanding 14.7 your actually at 12.5 ish

[1slowbusa]

I started over from the beginning because i believe i had everything out of wack. I think it looks much better now but i need some professional opinions. I have attached my program and scan with the car up to temperature.

Thanks

[1slowbusa]

Anyone have an opinion for me to get me started on the right track?

[WS6FirebirdTA00]

Coolant temp looks a little hot. Check you fan settings and coolant level (you may already know this but that is hot).

Depending how the car returns to idle, you may need to make the spark over and under speed tables more aggressive. Give it a few throttle blips and see how it does. May be just fine how it is though.

I just did a quick look, but most of the idle stuff looks pretty good. You will probably have to mess with the throttle cracker and follower tables too, I think the factory tables may give some issues with idle while rolling.

[tpcaz]

I have a 99 LS1 Trans Am. Currently using 1 Bar Enhanced MAF Operating System. It has stock heads and cam, but increased airflow with low restriction airlid/filter, Weiand Air Ram LS6 intake, ported & polished TB, mid-length headers, and MAC cat back exhaust. Running 32lb injectors and using the stock screened MAF.

When I was setting up my VE in SD, I had to take a stock 99 WS6 VE table and increase it by 15% just to get my AFR from running way too lean. My idle was still out so I used the RTT function to increase the cells used around idle. Even after this, I still had to tweak the VE table before going to re-cal the MAF. Looking at your VE table compared to mine and considering the mods you have, I would think your numbers would be much higher than mine. As mentioned before, this needs to be spot on before doing anything else. I tried to send you one of the available tuning guides out there but no matter what format I tried it exceeded the limits of this forum. I am sure at one time I found it on this forum.

[1slowbusa]

Thanks WS6FirebirdTA00, I will take a look at it somemore. My rear is about to arrive so it will be put on hold for a little bit.

tpcaz, I sent you a PM

[Ken]

I could use some advice on the idle air control logic for an LS motor please. I have just installed a 408 with FAST injectors, truck intake, and 102 mm TB. In order for it to start I have to put my foot into it and then warm it up at an RPM beyond my set point - approximately 1400 RPM. I believe when it warms to around 130 F the IAC starts to work and then it will idle on its own. The temp at which this occurs is where closed loop should happen as well. So, I am not sure what is causing this and I would appreciate hearing ideas. I have attached my tune for review if necessary. Thanks.

[WS6FirebirdTA00]

Post a log, that would help see what it is doing. Check out the stickies for the parameters to log.