I have Ls1 edit and my car starts fine on cold start-up. I just have problems with hot restarts. I have drilled the TB hole to 9/32 and still have to feather the gas peddle to start.

Any suggestions on what to modify on LS1 Edit, to help with this problem?

 

what do your IAC's on atap look like when the car is warm?

whats your timing at idle in park?

whats your idle RPM?

adding some timing down low helps a little with warm start ups. Go to the Base timing in park and drive tables and raise the timing in the 0-1200 cells down to the .2 row

mine was like 18 in the 0-800cells and 20 in the 1200 cells.. I raised it 2-3 degrees.

but welcome to the cam sucky idle club <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 98TAauto:
<strong>
but welcome to the cam sucky idle club <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">try running a 230/230 xe cam on a 111 LSA with our autos..... <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

I hate to do this to you guys , but my idle is perfect with the C1 (112). I have to admit it was a bit confused at first. I raised the base timing to 28 deg.,drilled the TB hole to 9/32, set the idle at 825/875 and it did some mild surging on occassion. I just had to tweek my idle screw to fine tune it. I then added a Shaner S2 TB and I never had to touch it again. The dealer even accidentally reflashed my pcm back to stock and it idled stable at the stock idle set point and timing and didn't die once for the two days it took MTI to reprogram my PCM back to perfection.
It can be a pain, but the car idles smoother and as stable as it did when it was stock. So it can be done. Good luck to you.

PS- my IACs are at 0 and have always been.

James

 

Something else to check in LS1edit is the AIC in park and AICs in gear. I think you can raise the AICs (temp)park for warm starts and AICs in gear for surging issues. Do a search in this section for "AIC idle park Drive". Someone here found the solution to fixing those few few sensative idle cars. It's here ya just have to find it. I'll post it if I come across the info. Good luck again.

 

Well I went back and tried to locate the thread and it appears that all of the previosly related posts are gone. I do know that there are some tables in LS1edit that allow changes in IAC temps that directly effect the idle and both warm/cold starts. The idle air controller opens a given amount based on the temperature range it is given. NOGO would be the ideal candidate for this project. I wish I could help more. Just be patient. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

There are three separate tables to change to help out with your idle.

In the engine section under Idle & Limiters, there are three tables on the left hand side that you work with to get a cammed car to idle right.

Idle Speed: You can raise this up a little bit to help with a cammed car. The problem is on automatics if you raise it too high the car will lurch when put into drive, or auto roll at 25 mph. With your cam, you should not need to go much higher than the stock RPM.

IAC Park Position: This table directly effects the IAC (the little servo in your TB that controls the amount of air into your engine with the TB closed). If you look at the table, you'll notice that for the colder temperatures the IAC position numbers are much higher than for the hotter ones. This is why your car starts like a dream on a cold day, but idles like crap on a hot one.
Change all cells for temperatures 20 deg C and up to 21. This should take care of your problem. If the car starts to erroneously high idle, then reduce this number until a happy number between idle and operation is found.

Idle Air In Gear: It is the same deal with this table, lots of air when cold, very little when hot. Multiplying the table by 130% should do the trick. Again, if the car starts to autoroll at 25 mph and the RPM's won't drop to a normal place, reduce this table in small steps until a happy medium is found.


The idea when trying to get a car to idle right with a cam is getting the right RPM / Air combo. If the car dies at stoplights and intersections, you need to increase one or both of these values. If the car auto rolls, or the RPMs stay erroneously high, then you have too much air, and you have to reduce it. It takes a couple tries, but is well worth it.
I usually tune a cammed car until I can *just* hear the lope.

Good Luck,
Kevin

<small>[ February 05, 2003, 03:41 PM: Message edited by: NoGo ]</small>

 

Thanks for all the help,

Last question, Where should the TPS volts read at idle?

 

"PS- my IACs are at 0 and have always been."

Use a different version of Autotap and I'll bet you'll see that this isn't really the case. Some versions show the IAC at zero all the time but if it really were at zero for very long you would get a code.

NoGo, thanks for the great information as always. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />

I have an internally stock engine and would you believe that occasionally it dies on me in gear during parking lot manuevers? I'm going to raise my idle air in gear a little bit.

 

NoGo, do you know what the three tabs under "Throttle Follower" are for?

Thanks. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

These tables control what we refer to in controls as the gain.

When you smack your throttle, you'll notice that your RPMs take a little bit before they come back down. These tables control how quickly they let the car return back to its idle RPM.

The tables also give an offset value to the IAC so it knows how much air will be rammed into the car with forward motion. If anybody has every drilled their throttle body hole too much, you will notice that the faster you go the freeway, the higher your idle when you put the car in neutral. The Airflow Decay in Gear gives a factor to allow the IAC to compensate for this.

Your IAC and motor will react only so fast to changes in air flow. As a result you need to let the car return to idle slow enough to allow the IAC to catch it. If you adjust it so the IAC instantly returnd back to its idle position after you come off of the gas the RPMs will fall so fast that by the time the IAC opens to control the idle the RPM will have dropped low enough to kill the engine.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by ANIL8U:
<strong> Thanks for all the help,

Last question, Where should the TPS volts read at idle? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">.6 volts

 

Good discussion. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I've raised my timing and IACs too. Raising the IAC helped get rid of cam surge, but definitely resulted in a cruise control effect on lift throttle coasting.

I've been able to use higher than stock IAC when warm, but less than used by No Go. However I suspect the exact needs are also a function of the TB hole size and timing added. Changing the idle timing effects the idle IAC count.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> If anybody has every drilled their throttle body hole too much, you will notice that the faster you go the freeway, the higher your idle when you put the car in neutral. The Airflow Decay in Gear gives a factor to allow the IAC to compensate for this.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">What change in the table values do you recommend to counter that problem?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ragtop 99:
<strong> Good discussion. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I've raised my timing and IACs too. Raising the IAC helped get rid of cam surge, but definitely resulted in a cruise control effect on lift throttle coasting.

I've been able to use higher than stock IAC when warm, but less than used by No Go. However I suspect the exact needs are also a function of the TB hole size and timing added. Changing the idle timing effects the idle IAC count.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> If anybody has every drilled their throttle body hole too much, you will notice that the faster you go the freeway, the higher your idle when you put the car in neutral. The Airflow Decay in Gear gives a factor to allow the IAC to compensate for this.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">What change in the table values do you recommend to counter that problem? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">If you have cruise control happening, then you have too much air getting in with the IAC park position.
Adjusting the throttle follower just controls that RATE at which your car will return to its normal idle speed, not your actual idle speed.
My point was that extra air is getting into your engine when you are moving forward. If the IAC didn't take this into account then it would take forever for your RPMs to come down after you get off of the gas on the freeway.

To get rid of your cruise control, you can try raising your idle speed and reducing the IAC count a little bit.

 

Thanks, I will try this out on sat!

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> If you have cruise control happening, then you have too much air getting in with the IAC park position.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks.

I have been reducing the IAC Count in Gear which seems to have helped, but I'll also check the Park table too.

 

Successful hot restarts, I moved the cells to 11 from 6. It idles a little high for a sec then comes down to 950 out of gear and 850 in gear.

Thanks NoGo


<img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by ANIL8U:
<strong> Successful hot restarts, I moved the cells to 11 from 6. It idles a little high for a sec then comes down to 950 out of gear and 850 in gear.

Thanks NoGo


<img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">which tables did you edit?? did you do anything to the in gear table neutral cells??

 

NoGo,

What version of EDIT lets you change IAC numbers? On this computer i have version 1.04. Does version 1.05 let you change IAC numbers?

 

For my personal version of edit I use 1.21