H/C Swap completed, Quick Idle tuning question.
H/C Swap completed, Quick Idle tuning question. Thanks in advance for any help.
I read through the ls1tuninfo.doc file and had a question about it. Specifically this part here. Question 1: Can anyone clarify exactly where this table is and what the values need changed to?
Without knowing that, I moved on and started following through these steps. I believe I got the idle speed set correctly. Here's a screen shot of it if anyone can tell me if I did this right I'd appreciate it.
Question 2: Where are the spark tables located that I need to set the park and drive idle values to about 22 degrees? Is this it?
That's all the farther I have gotten with getting the car to idle because I wasn't sure on these items and wanted to double check before I tried anything.
Thanks,
Dennis
I read through the ls1tuninfo.doc file and had a question about it. Specifically this part here.
Idle Tuning
To set idle speed go to VCM Editor>Edit>Engine>Idle>Idle RPM>Target Idle RPM vs. ECT table and change cell values to desired idle RPM. If idle RPM is modified up or down, the VCM Editor>Edit>Engine>Idle>Base Running Airflow>Idle Airflow vs. ECT table must be adjusted up or down also.
To set idle speed go to VCM Editor>Edit>Engine>Idle>Idle RPM>Target Idle RPM vs. ECT table and change cell values to desired idle RPM. If idle RPM is modified up or down, the VCM Editor>Edit>Engine>Idle>Base Running Airflow>Idle Airflow vs. ECT table must be adjusted up or down also.
Without knowing that, I moved on and started following through these steps.
A Basic Idle Tuning Strategy
1. Set idle speed to desired RPM. 900-950 is good for cars with aftermarket cams.
2. Go to all your spark tables and set the park and drive idle values to about 22 degrees.
3. Now switch to a scanner that lets you see IAC counts and TPS voltage. This is where we will spend some time.
4. We want IAC counts to be 40-60 for cars with aftermarket cams. The stock cam runs about 60-80 counts. A car with an aftermarket cam will want less IAC counts.
5. To reduce IAC counts turn off the car. Turn the idle set screw clockwise to open the throttle blade a LITTLE. Unplug the TPS, turn the key to the on position, DO NOT start the car, for 30 seconds. Turn the key off and plug TPS back in.
6. Start the car and begin scanning. Monitor the IAC counts and repeat step 5 until the IAC counts come into line. It will take about 4-6 times to get the IAC counts correct.
Note: Keep in mind that TPS voltage must be in the .4 to .6 range. If above or below this voltage, the PCM will fall into the wrong cell at idle. Check the TPS voltage each time the set screw is adjusted and adjust as necessary.
1. Set idle speed to desired RPM. 900-950 is good for cars with aftermarket cams.
2. Go to all your spark tables and set the park and drive idle values to about 22 degrees.
3. Now switch to a scanner that lets you see IAC counts and TPS voltage. This is where we will spend some time.
4. We want IAC counts to be 40-60 for cars with aftermarket cams. The stock cam runs about 60-80 counts. A car with an aftermarket cam will want less IAC counts.
5. To reduce IAC counts turn off the car. Turn the idle set screw clockwise to open the throttle blade a LITTLE. Unplug the TPS, turn the key to the on position, DO NOT start the car, for 30 seconds. Turn the key off and plug TPS back in.
6. Start the car and begin scanning. Monitor the IAC counts and repeat step 5 until the IAC counts come into line. It will take about 4-6 times to get the IAC counts correct.
Note: Keep in mind that TPS voltage must be in the .4 to .6 range. If above or below this voltage, the PCM will fall into the wrong cell at idle. Check the TPS voltage each time the set screw is adjusted and adjust as necessary.
Question 2: Where are the spark tables located that I need to set the park and drive idle values to about 22 degrees? Is this it?
That's all the farther I have gotten with getting the car to idle because I wasn't sure on these items and wanted to double check before I tried anything.
Thanks,
Dennis
11 Second Club
Joined: May 2003
Posts: 764
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From: Glasgow, Ky
Idle looks ok, but if it were me I'd have it staggered like it was from the factory. 1050,1000,950,900,etc... They do that for a reason you car doesn't idle @ -40° like it does @ 150°. As far as the idle spark look under Spark Advance, I believe there is the table you are looking for, it's hard to remember without looking at it. If you are getting cam surge (Erratic RPM's at idle) The running airflow table is where you want to make your adjustments.
The Base spark "in drive" and "in park" tables are located at VCM Editor -> Edit -> Engine -> Spark Advance. If you look on the left there is the two buttons for High Octane and Low Octane Spark tables. Right under then is the IN DRIVE and IN PARK tables for Base Spark.
Dixit
Dixit
i dont agree with a majority of the information in that write up. for one i would lower those rpms at idle to about 850. i can get my car to run to 700 rpms with a 230/232 cam and yours is pretty close to mine. i see no need to idle that high. for the timing, go to vcm controls and play iwth the timing while the car is running. you can add and subtract. this will find the best idle for your car. plus you want to get the high octane table in line with the idle spark setting, you dont want it to be a huge difference or else it can cause some bucking at low throttle and speed. ive got a good bit of info on here on stuff i did to my car to get the idle all set up, might be a little overkill but i think it was well worth it.
Originally Posted by 99FormulaWs6
Idle looks ok, but if it were me I'd have it staggered like it was from the factory. 1050,1000,950,900,etc... They do that for a reason you car doesn't idle @ -40° like it does @ 150°. As far as the idle spark look under Spark Advance, I believe there is the table you are looking for, it's hard to remember without looking at it. If you are getting cam surge (Erratic RPM's at idle) The running airflow table is where you want to make your adjustments.
Picture explains it much better.
Now, as far as spark advance goes, should I let it have variation too, or just change everything to 22* like that document says to go through.
Thanks.
Originally Posted by WS6FirebirdTA00
i dont agree with a majority of the information in that write up. for one i would lower those rpms at idle to about 850. i can get my car to run to 700 rpms with a 230/232 cam and yours is pretty close to mine. i see no need to idle that high. for the timing, go to vcm controls and play iwth the timing while the car is running. you can add and subtract. this will find the best idle for your car. plus you want to get the high octane table in line with the idle spark setting, you dont want it to be a huge difference or else it can cause some bucking at low throttle and speed. ive got a good bit of info on here on stuff i did to my car to get the idle all set up, might be a little overkill but i think it was well worth it.
We need a walkthough like the H/C walkthrough and stuff on ls1howto covering exactly what to go through after a cam swap is done. Oh well, I'll figure it out eventually.
11 Second Club
Joined: May 2003
Posts: 764
Likes: 0
From: Glasgow, Ky
Originally Posted by davis80
So then anything that falls below my desired idle speed. Let's say 800 rpm, change all the values that are less than 800 to 800, and then anything over 800 leave the stock value there?
Picture explains it much better.
Now, as far as spark advance goes, should I let it have variation too, or just change everything to 22* like that document says to go through.
Thanks.
Picture explains it much better.
Now, as far as spark advance goes, should I let it have variation too, or just change everything to 22* like that document says to go through.
Thanks.
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those write ups will get you on the raod to make it somewhat driveable. what we are explaining will help the car run like stock. if you have any questions email me and ill send you the info you need to get your idle set up. budchevy358@yahoo.com is my email.
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Originally Posted by 99FormulaWs6
Actually, what I did was added 50(100 or whatever idle you want) to the entire table, that way the flow stays the same, You live in the south so you're probably not going to see a whole lot of sub 30° weather. So what I would do is add until you get 25+ in the 800-850 range. Add whatever it takes to get it there. WS6Firebird is correct, what I would do is open my scanner and go to the VCM control and let your car sit and idle and add spark until you hear the correct sound 19-22 is where I would guess, but I'd try 19, 20, 21, 22 and see what sounds better. Then add that to your P/N table.
This is probably a simple explanation and I'm just confused, but when you say "you added 50(100 or whatever idle you want) to the entire table" What exactly did you add 50 to? What was the base value that you started with?
11 Second Club
Joined: May 2003
Posts: 764
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From: Glasgow, Ky
ok, if your stock idle is 850@25° and you want it to idle @ 950 then highlight the entire table and add 100.(Target idle speed) that way it retains the stock curvature, but adds enough RPM to keep your car running. Your car stock will idle faster when cold, and slow when hot, you want to keep this, GM actually does know a thing or two about cars, well sort of. Does that clear anything up?
Originally Posted by 99FormulaWs6
ok, if your stock idle is 850@25° and you want it to idle @ 950 then highlight the entire table and add 100.(Target idle speed) that way it retains the stock curvature, but adds enough RPM to keep your car running. Your car stock will idle faster when cold, and slow when hot, you want to keep this, GM actually does know a thing or two about cars, well sort of. Does that clear anything up?
Even with these changes the car would not idle at all. I sat in the driveway for 10 mins feathering the throttle and it would never find idle. I took it around the block but it's such a huge pain in the *** because I have to pull up to a stop sign basically power braking the car to keep the RPMs up high enough to keep it running.
This is getting really frustrating. My IAC counts are up around 140-160 right now but that's probably higher than actual since I can't get the car down to idle speed.
ill get those files to you tonight if i get a chance, last night i was real busy and didnt have time. you may have to open the tb to read about .61 v on the tps to get the counts down as well. whats your idle airflow numbers like right now?
Originally Posted by WS6FirebirdTA00
ill get those files to you tonight if i get a chance, last night i was real busy and didnt have time. you may have to open the tb to read about .61 v on the tps to get the counts down as well. whats your idle airflow numbers like right now?
When logging, I keep getting connection errors when the idle drops too low and it has to reconnect so it's been kinda frustrating.
the connection errors are the shitty serial cables, mine does it all the time and ive got to go get something to plug in the computer that will work better and is a little stronger wire
11 Second Club
Joined: May 2003
Posts: 764
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From: Glasgow, Ky
Is the idle hunting or is it completely dieing? Send me your log file too please.
owens.carl@gmail.com
owens.carl@gmail.com
idle is not hard to do, because you can find out what your car 'likes' simply by playing with live controls. you can find IAC steps, rpms, and timing that make it idle nicely, and then populate all the appopriate tables to match these values. the only thing you really want to adjust by more extensive scanning is RAF table, and dropping IAC counts to 30-60 with the idle control screw on the TB (use the 5/64th torq) while monitoring your TPS voltage. once you find a comfy IAC range, reset your TPS sensor (turn off car, disconnect IAC sensor, start car, turn off car, reconnect IAC) and you should be good.
Originally Posted by WS6FirebirdTA00
the connection errors are the shitty serial cables, mine does it all the time and ive got to go get something to plug in the computer that will work better and is a little stronger wire
Originally Posted by 99FormulaWs6
Is the idle hunting or is it completely dieing? Send me your log file too please.
owens.carl@gmail.com
owens.carl@gmail.com
Originally Posted by RedHardSupra
idle is not hard to do, because you can find out what your car 'likes' simply by playing with live controls. you can find IAC steps, rpms, and timing that make it idle nicely, and then populate all the appopriate tables to match these values. the only thing you really want to adjust by more extensive scanning is RAF table, and dropping IAC counts to 30-60 with the idle control screw on the TB (use the 5/64th torq) while monitoring your TPS voltage. once you find a comfy IAC range, reset your TPS sensor (turn off car, disconnect IAC sensor, start car, turn off car, reconnect IAC) and you should be good.
As far as adjusting the throttle body to lower IAC counts, will I just have to turn the set screw, start the car up and do it that way? The car won't run at all without me in it and peddling.
first do VE/timing, that stops it from surging. then you bring down your IACs and you should be close enough to then get some data for RAF tables, and then it will idle butter smooth
Originally Posted by RedHardSupra
first do VE/timing, that stops it from surging. then you bring down your IACs and you should be close enough to then get some data for RAF tables, and then it will idle butter smooth
But that's stupid
ill give you a hand, it doesnt take long to set up. you may be really rich right now if you have not tuned the Ve. i sent you the 2 files, if you log with those and send the scans to me ill let you know what has to be done. i dont have hp tuners for 98 so i cant save any info to a tune for oyu i have to tell you what to change.