Need help getting car to idle when cold

[Dukenukemx]

Since I put a cam in my 02 Vette I can't get it to idle unless I let the car warm up. It'll idle just fine when I crank the engine, but it's when I shift into gear it just stalls. Once I warm it up this isn't a problem, but it takes a while to warm up like at least 5-10 minutes. I've increased the airflow and the idle but doesn't seem to matter since putting it into drive or reverse will just stall it out. What other values can I change in TunerPro to correct this? The OS is 12221588.

[ralmo94]

Did you ever get a wideband o2? If you did, you could tune the warm up enrichment
If not, what are your O2 readings before it goes cl, pegged, or almost 0?
Is it cl when it does this? Maybe keeping ol longer, or going cl sooner would help?

[Dukenukemx]

Did you ever get a wideband o2? If you did, you could tune the warm up enrichment
If not, what are your O2 readings before it goes cl, pegged, or almost 0?
Is it cl when it does this? Maybe keeping ol longer, or going cl sooner would help?
No wideband yet. I figure that's for next year when it isn't so cold. I do have the trans cooler but not installed for the same reason. I don't have a garage to park my car in. I never looked to see what the O2's are reading. I'll give it a try tomorrow and see what they say.

[Dukenukemx]

I did a quick startup at idle and logged it but it didn't report short term or long term trims until it warmed up a bit which took a few minutes. I then saw it report -22% and then slowly climbed up to around 0%, which I then put the car into drive and reverse and it didn't stall. So I guess that means I'm running too lean? Is this something I adjust in the VE table or there's another set of variables that control startup idle? I would have guessed it ran too rich just from the smell of the exhaust.

[ralmo94]

it report -22% and then slowly climbed up to around 0%,
So I guess that means I'm running too lean?
I would have guessed it ran too rich just from the smell of the exhaust.

-22, means it is taking 22 percent out, that is rich.


Is this something I adjust in the VE table or there's another set of variables that control startup idle?

There should be a table of commanded ratio per engine temp, and possibly a warm up multiplier?
You don't want to change VE, you already tuned it.

[ralmo94]

I found a Stock file on HPT Respository
Here is the table and HP description

[ECM] 12430 - Open Loop F/A vs. Coolant Temp vs. MAP: This table is used to determine the commanded AFR when in open loop mode. It divides the Stoich AFR value. AFR is determined by 14.7/table value. Example: 14.7/1.30 = 11.3 AFR
18678
I don't know how it is labled in UP

[Dukenukemx]

I found a Stock file on HPT Respository
Here is the table and HP description

[ECM] 12430 - Open Loop F/A vs. Coolant Temp vs. MAP: This table is used to determine the commanded AFR when in open loop mode. It divides the Stoich AFR value. AFR is determined by 14.7/table value. Example: 14.7/1.30 = 11.3 AFR
18678
I don't know how it is labled in UP
I think I found it. I think it's called B3605 Open Loop Commanded Fuel. Should I just decrease everything by 20%? I have an original bin I found to compare and it does seem like the values were increased, but slightly. On average it's a good 0.20 higher than the factory settings.

[ralmo94]

I would just set it to the stock values, and adjust from there, IF NEEDED.

[Dukenukemx]

I would just set it to the stock values, and adjust from there, IF NEEDED.
I set it to stock then lowered everything by 20% and the car wouldn't run in park. Went back to stock and increased it by 15% which made it idle so much better. Still stalls if I put the car in drive or reverse unless I give it a good 2-3 minutes. But yea it idles far better now, so I lowered the idle and park RPM as well as idle air flow. Maybe I could increase it another 5% to see if that corrects it or maybe it needs an idle relearn? Maybe I should lower the temp needed for closed loop? Also I noticed that B4206 STFT Open Loop Enable is enabled while the original setting was off. Not sure what that does?

[Trgrhpy]

Hey Duke,did you ever determine what B4206 does I'm curious also. What became of your idle issue, fixed?

[Dukenukemx]

Hey Duke,did you ever determine what B4206 does I'm curious also. What became of your idle issue, fixed?
I haven't done anything to the Vette since as I've also been busy dealing with my other cars which need fixing. I did flash yet another change to the tune as I did increase the open loop table by another 5% and I also smoothed it out. It didn't help so much for the idle but it drives better until closed loop. As it is right now I gotta wait a good 30 seconds before shifting the car when cold. In the summer this isn't an issue. I'll upload what I did last to the tune. As for B4206 I never did turn it on. It allows open loop to use the O2 sensors, but I'm not sure if that's a good idea or not? I doubt it'll solve my cold start idle. More specific it'll idle just fine in park or neutral, just not when I shift into drive or reverse. 30 seconds is an improvement compared to before, especially when compared to Chucks tune. Had to give the car a good 3 minutes or more before shifting it into gear. Still haven't bought a wideband sensor yet, but form the looks of the prices, that might have been a good thing. Prices have come down a lot last I checked. I don't plan to make it a permanent part of the car, mainly because I'd want to use the wideband on my Porsche 928 as well, if I can ever find a way to tune that car. I think I now have a way to tune my uncle's 07 Tahoe as well, and try to use what I've learned here to boost his performance and MPG. Next year.

[Trgrhpy]

Duke, I loaded your bin in TunerRT, sourced a 12221588 xdf and took the attached screenshot. Doesn't it show that B4206 is enabled? This xdf describes the 4206 very well, the xdf for my car doesn't have a description at all. It seems the xdf can make a huge difference. Some xdf's reference table temperatures in C and some in F, some a mixture of both. Doesn't matter as long as you know that and don't assume all tables are one or the other. I attached this xdf file in case you want it.
18769

[In-Tech]

Hiya,
Did you ever post your stock file? I can modify your stock file that will probably run better than you can purchase, so can many here and get you a good starting so you can fine tune.

No offense, but, you are focking around in areas you shouldn't be. Just because you have software and a laptop, doesn't make you a tuner. Again, no offense. It's truly why older facks don't even reply.

When I get hired to tune, very many times it is because they have paid some other fack to do it...Of course they believe because they don't know anything. It sucks to go into a job and charge twice as much as they have already paid to some fack.

[Dukenukemx]

Duke, I loaded your bin in TunerRT, sourced a 12221588 xdf and took the attached screenshot. Doesn't it show that B4206 is enabled? This xdf describes the 4206 very well, the xdf for my car doesn't have a description at all. It seems the xdf can make a huge difference. Some xdf's reference table temperatures in C and some in F, some a mixture of both. Doesn't matter as long as you know that and don't assume all tables are one or the other. I attached this xdf file in case you want it.
18769
That's one of the XDF's I've been using. I tend to switch between some, and even use Universal Patcher. I guess I turned on B4206? I don't remember doing that. Looking at previous bin's, it looks like I've had that on for a while. Probably a desperate attempt to get it to idle better.

Hiya,
Did you ever post your stock file? I can modify your stock file that will probably run better than you can purchase, so can many here and get you a good starting so you can fine tune.
Don't have a stock file because I trusted a guy named Chuck from Westchester Corvette to do the tune. Then when I actually drove the car for a long distance it burned so much fuel and didn't operate the way I wanted. After a lot of help from the community I then realized that Chucks tune sucks. I honestly think he went onto HPTuners repository and grabbed whatever he could find and made some changes for my car and then charged me $1k.


No offense, but, you are focking around in areas you shouldn't be. Just because you have software and a laptop, doesn't make you a tuner. Again, no offense. It's truly why older facks don't even reply.

You have no idea how many times I've heard that phrase, only to end up knowing more than those that do. If you don't fock around, then how do you not find out? I liked it when I did lap the valve's on my Vette's heads and I called it a "Valve Job", machinists would chime in and remind me that a proper valve job is this and that. Ok then I will call it a lap job. I don't care to be called a tuner if my car runs the way I want it.


When I get hired to tune, very many times it is because they have paid some other fack to do it...Of course they believe because they don't know anything. It sucks to go into a job and charge twice as much as they have already paid to some fack.
At this point my Vette feels faster and I'm getting so much better MPG. More importantly, it's more drive-able. A remote tune without any data log isn't going to do me much good without me feeding you data constantly. At this point I need a wideband and to log it, and then let Trimalyzer further adjust the VE table. Maybe mess around with Power Enrichment some more.

[keigger73]

what size cam did you swap in? you may need a stall converter? I'm not sure what trans you're running or if it has some stall built into its converter? the stock 4L60E has 1650 but I'm not sure if that's your setup or not just my 2cents, hope you get it lined out

[In-Tech]

Hiya Dukenukem,
I am glad to hear you are making good progress. I had kinda been following you since you started this quest and noticed a difference in the vin numbers in your .bin files. Which vin is correct? I'm not sure it's an issue but the parameters area of the files between vins are quite different. Before I buy a vin cal, I'd like to make sure I am getting the right one :)

[Dukenukemx]

what size cam did you swap in?
It's a Brian Tooley BTR Stage 2 with specs being 227/238 .620"/.605" 113.5LSA.


you may need a stall converter? I'm not sure what trans you're running or if it has some stall built into its converter? the stock 4L60E has 1650 but I'm not sure if that's your setup or not just my 2cents, hope you get it lined out
It's a ProTorque torque converter 3200 that I bought from tabbruzz from the Corvette forum. He's the reason that I got started down this path of self tuning my Vette. When I had my Vette tuned by Chuck of Westchester Corvettes, it took him 2 months plus I got it back with a bad trans. The car has 96,000 miles and I did drain and fill the trans once in it's life, but the fluid was black like motor oil black. This is the thread that started it. (https://www.corvetteforum.com/forums/c5-tech/4673038-new-cam-and-tune-getting-horrible-gas-mileage.html) I bought a junk yard transmission that had been rebuilt in the past, but I doubt it was rebuilt to deal with more power. Took me 11 hours straight swapping the trans.


Hiya Dukenukem,
I am glad to hear you are making good progress. I had kinda been following you since you started this quest and noticed a difference in the vin numbers in your .bin files. Which vin is correct? I'm not sure it's an issue but the parameters area of the files between vins are quite different. Before I buy a vin cal, I'd like to make sure I am getting the right one :)
I might have uploaded a lot of bins from different sources to compare, but the one I'm using has the same vin as the tune I extracted that was done by Chuck. The thread that I learned to tune was here which ralmo94 helped me a lot with. (http://www.gearhead-efi.com/Fuel-Injection/showthread.php?11288-Need-compatible-cable-or-device-for-TunerPro) I also got help from Pulse_GTO from LS1tech forum. (https://ls1tech.com/forums/pcm-diagnostics-tuning/1962019-such-thing-cheap-vcm-suite.html) Pulse_GTO was able to help me revert the transmission back to the way it was, even though I did adjust the tune a bit more aggressively since. There isn't a lot of information that helps with tuning with free software, so these threads are great for reference.

[Dukenukemx]

Just updating that I finally got around to trying my Vette and did some changes to the idle. I raised the idle higher, especially when I have the A/C on since it really likes to die when that's on. I also raised the air flow a bit when it's colder, since that may help keep it running. What I've noticed is that once it learns to idle, it stays running, but it seems to forget once I shut off the car for too long. What I do is keep my food on the gas peddle when I put the car into reverse or drive to make sure it doesn't accidentally stall out, but when it learns it doesn't have this problem. Since I modified Chucks original tune, I wonder if he just turned off idle relearn, or maybe since the car doesn't get hot enough that an idle relearn doesn't occur? Not sure how a 2002 Corvette learns to idle, but in most GM cars of this era you just let it idle and get it hot enough to let the fans kick on. Since I have a 160 thermostat that might make idle relearn difficult. I do have the trans cooler on as well, so the car generally runs much cooler than stock. I'm probably going to play around with lean burn mode since I get the strangest MPG. It's really good if I cruise from 30-40 the way I have it setup, and once lean burn kicks on which is closer to 50, it's also really good, but past 60mpg I'm getting 22mpg or 24mpg, but closer to 70 it's more like 30mpg. I uploaded what I've done to correct the idle so far.

[Dukenukemx]

Uploading my latest idle tune. This one has a lot of changes for good reasons. Firstly I lowered the A/C idle because putting on the A/C did make the engine jump up a lot in idle, so I just made it nearly equal to P/N but 25 RPM higher instead of 100. I then messed with the timing for idle, because I did change the Drive timing to 25, but at 1200 rpm it was set higher for some reason. I made everything 1200 RPM and bellow set to 25, as I've tried 20 and 30 with poor results. Plus I changed the P/N timing as it was set to nearly stock, which was 18. So I changed that to 25 along with the rest of the power curve getting a 4 timing increase to roughly match Drive. I also changed it so when the engine RPM drops or increases it doesn't suddenly increase or decrease timing. I then altered the lean cruise mode so the timing is more aggressive when it activates, plus it runs more leaner too.

So far the results are much better. I can now start the car and drive it without worrying about it stalling. Turning on the A/C is a bit too much at the start but the more I drive it the less of a problem it is, as if the car learns with each time I drive it. The gas mileage is better, but it's weird as it's really good at 50 to 55 MPH like almost 40mpg, but drops to 22MPG when doing 60 to 65 MPH, but goes back up again to nearly 40 at 70 MPH. I'm sure once I have the wide band sensor I can better properly tune this, which is still in the plans. I may also in the future reduce the idle airflow as I have it set to 11, and that maybe too much as at times it feels like cruise control, but it's rare. When I get the wideband installed I'll probably drop that a bit but for now it idles and drives well so I don't want to mess that up.