Idle tune

[white2001formula]

I was hoping to find someone locally that can do some idle tuning on my car. I can't deal with this lope anymore. I have LS1Edit to. I'll buy a wideband if need be. I had the car dyno tuned years ago, and accepted it as being normal. I've talked with many people who had crazier setups, and beter idle quality.

The symptoms are on an idle while slowing down. It will begin to lope way down low. For instance, while coming to a red light, slowing down under 20mph. Once it's stopped, the idle levels out and it's normal. This has happened since day one. It's not something new.

Years ago, I set the idle screw out a bit, and drilled out the TB just a bit. Both of those seemed to help.

Specs are Stage 2 PP 5.3 heads
225/225 .589/.589 112 LSA
Full Intake/Exhaust
Auto w/3200 Vig Stall

Thanks,
Chris

[Damian]

Years ago, I set the idle screw out a bit, and drilled out the TB just a bit. Both of those seemed to help.

There's two of your problems.

Neither are necessary with tuning software.

If you have LS1edit, you should be able to go in and adjust your base running airflow. Raise it up 2.0 after 46* and the car should idle fine. A 225 duration cam shouldn't be giving you any idle problems unless there's something else wrong with the car. FYI a wideband isn't really necessary unless you're tuning WOT.

[white2001formula]

I've talked to a lot of people, and they said the same thing about the idle. I'll look at that table if it's available in my prehistoric version of LS1edit this weekend.

Thanks Damian,
Chris

[Damian]

If you can, try and find a stock TB blade that hasn't been drilled. It's easier to tune that way, so you're not fighting IAC counts. I hate tuning cars with drilled TB holes.

[white2001formula]

I'm already one step ahead of you on that. I'm working with someone on LS1Tech to get an unmolested TB or a simple TB Blade. However, I think I just drilled out 1/16" or 1/8" above what it was stock. I moved up by 1/32" two or three times when i drilled it out.

I also just picked up a stocker MAF to rule out everything. I had a GMAF.

I will look into the table you mentioned when I can find a damn computer w/Windows 2000, or get that OS loaded on my mini HP. LS1Edit version 1.ancient.old doesn't like XP so much.

-Chris

[Gh0st]

Originally Posted by Damian

There's two of your problems.

Neither are necessary with tuning software.

If you have LS1edit, you should be able to go in and adjust your base running airflow. Raise it up 2.0 after 46* and the car should idle fine. A 225 duration cam shouldn't be giving you any idle problems unless there's something else wrong with the car. FYI a wideband isn't really necessary unless you're tuning WOT.

What an incorrect crock of shit. I can't believe a sponsor is seriously advising that someone leaves their airflow tables stock with a modified engine

[Gh0st]

Originally Posted by white2001formula

I'm already one step ahead of you on that. I'm working with someone on LS1Tech to get an unmolested TB or a simple TB Blade. However, I think I just drilled out 1/16" or 1/8" above what it was stock. I moved up by 1/32" two or three times when i drilled it out.

I also just picked up a stocker MAF to rule out everything. I had a GMAF.

I will look into the table you mentioned when I can find a damn computer w/Windows 2000, or get that OS loaded on my mini HP. LS1Edit version 1.ancient.old doesn't like XP so much.

-Chris

Without proper airflow tables your adjustments are always going to be a hack. Trust me, the car will run a lot better when it's properly tuned. Relying on fuel trims to do the tuning for you is a sign of a lazy tuner or someone who has no idea what they're talking about.

[edcmat-l1]

Originally Posted by Gh0st

What an incorrect crock of shit. I can't believe a sponsor is seriously advising that someone leaves their airflow tables stock with a modified engine

I don't use a WB for tuning idle. I guess I suck.

[Gh0st]

Originally Posted by edcmat-l1

I don't use a WB for tuning idle. I guess I suck.

You don't need one to get a car to idle but leaving the airflow tables stock is just plain stupid and you know it.

[Damian]

What an incorrect crock of shit. I can't believe a sponsor is seriously advising that someone leaves their airflow tables stock with a modified engine

First, I'm not a sponsor anymore, dipshit. Second, the OP's problem is simple and doesn't require a wideband to remedy. You really need a wideband to get a 225 duration cam to idle? Really?

[FL Junkie]

i know this is the basic part, but did you zero out the throttle cracker and the throttle follower delay? how do your IAC tables look?

[edcmat-l1]

Originally Posted by Gh0st

You don't need one to get a car to idle but leaving the airflow tables stock is just plain stupid and you know it.

I didn't say that. You jumped on Damian for not using a WB for idle tuning. I made a statement that I don't use a WB for idle tuning.

[white2001formula]

I appreciate all the responses so far. Currently, I don't have the ability to look at my latest LS1Edit file. I have to find a computer with Windows 2000, because of the old version I have.

I will check out the IAC, Throttle tables, and Base Running Airflow tables. It should take a few days for me to do this. I don't know if all the tables will be available though, I haven't looked at LS1Edit in quite some time.

I will report back as soon as I get this info. It will probably take a few days.

[white2001formula]

Should have the hardware to hook up to the PCM tomorrow. I searched my Users guide for my LS1Edit version 1.21. Here are the following tables I found. No "Base Running Airflow" tables were really found. I may need to buy a newer version of a tuner.

P/N Delay

Delay in seconds that Throttle is held after letting off throttle, before allowing the decay listed in “P/N Airflow Decay”

Airflow Decay In Gear
Allowed Airflow decay in Grams per second per 12.5 Milliseconds when in Gear.

P/N Airflow Decay
Allowed Airflow decay in Grams per second per 12.5 Milliseconds when in Park or neutral.

Originally Posted by Damian

There's two of your problems.

Neither are necessary with tuning software.

If you have LS1edit, you should be able to go in and adjust your base running airflow. Raise it up 2.0 after 46* and the car should idle fine. A 225 duration cam shouldn't be giving you any idle problems unless there's something else wrong with the car. FYI a wideband isn't really necessary unless you're tuning WOT.

[hmorris7000]

whats going on man!! told ya josh would get you right!!

[Damian]

Whiteforumla, if I were you, I'd be looking over your motor for any type of vacuum leak or mechanical issue first. Unless you got the wrong cam, no way should a 225 cam have problems idling, even with a stock tune. The 228/232 cams I use will idle on a stock tune, hell even my 230/238 cam will idle on a cold start without any tuning. I think there's an issue somewhere.

Check for leaks around the MAF, TB gasket, or MAP sensor. Log your fuel trims at idle and tell me what they're doing. I just find it tough to swallow that a 225 cam won't idle.

[white2001formula]

Damian,

I will check those to. I am loading up Windows 2k & LS1Edit as we speak on an old laptop. I'll be able to post up my last LS1 Program.

I also have thought about pulling all the intake/vacume one evening and give the seals/gaskets a good look over.

I have no rear OS's, so can I log LTFT's?

-Chris

[white2001formula]

Pictures like I promised.

LS1Edit.bmp: Picure showing all the available sections
Engine--idle limiters.bmp: Picture showing 4 tabs available under Engine Calibration
IAC-Park: IAC Park Position Airflow (Graph)
Running-Airflow.bmp: Damian, I believe to the best of my knowledge, that this is the Base Running Airflow you mentioned.

When I get home, I am going to pull the most current LS1Edit file. I just looked (edited this post) and those were before my tuning was done.

[white2001formula]

Alright, valid data now. Here are the pictures. How high can I go on these values before it's something mechanical?

Stock Idle table
Idle table I dealt with before
Idle table that I'm about to upload

[white2001formula]

Just got back from a nice little drive around town. It idle's better, much better actually. I am going to pull the Intake Manifold this weekend and double check some stuff.