Idle fueling

[sabastian458]

I have searched and read about 2 dozenish threads and the idle under the sticky at the top and have yet to find a direct enough answer.

I have been working on my VE and MAF settings and have them dialed in as close as I can. I have also worked on the idle when putting in neutral. (manual car)

My issue is that when I start the car dead cold (50-60F) It starts up, RPM's hunt up and then down 2-3 times, finds the correct idle level and hold. How do I correct that? I have tried adding and subtracting a little ammount from the startup airflow table with horrible results (car will not start at all)

Then as it is warming up my Lambda ERR% is correct (.02-.05% +/-) until my disired idle RPM gets below 1000. Then the Lambda ERR% is lean by .22% and the exhaust has enough unburnt fuel to burn your eyes.

I have tried to add airflow in the main VE table and base idle airflow final min table to no avail. What table should I be modifing to correct this?

[E85 LSX]

If you added a cam with alot of overlap it could explain your fueling issue. With a larger cam you will have to change the injector boundries at idle. . .moving the time of injection later. . .

a stock car will inject the fuel on the back of a closed intake valve which will result in the fuel exiting out the exhaust valve when the intake opens and the exhaust valve is still open because of the bigger cam and its overlap. If you still have cats this could be overheating them.

Now if you move the injection time later you will be injecting into an open cylinder so u risk bore wash but the exhaust valve will b closed and the fuel you want to deliver to the cylinder will actually stay in their.

[sabastian458]

no cats on my car

I used the injector info from Greg's dvd. Guess I need to play arround and see where my car likes to have its injection timing

[sabastian458]

I cant post the tune with the injector information as it is copyrighted

I am currently in SD with the long and short trims disabled, and I dont have an IAC, im Drive by wire. I can post a few of the logs tho?

[WS6FirebirdTA00]

What injectors do you have and why can't you post it?

Just delete the injector tables then.

[69lt1bird]

Who said you can't post your tune with Greg's injector data in the file. How in the hell are people supposed to get any help with their tunes if this is what it has come too.

[sabastian458]

ok, I am working on emailing my tune to DOGN. I will also delete the injector data that I got from Greg's dvd and then post it on here. I am running siemmons 60's long style. My tune has been scaled 80% based off of the attached file. I greatly appreciate ya'lls help.

I have tried uploading my tune fine a dozen times and it wont load. Just keeps saying "uploading file- please wait"

[sabastian458]

i have been trying to upload the tune file all day and it will not let me.

[sabastian458]

been reading alot of old threads and found one that I think will help with the fuel smell

http://www.hptuners.com/forum/showth...njector+timing

[sabastian458]

ok so in the "injection Boundary" table I added 35 degrees to what was there (520) for a total of 555 in cells from 0-1024, and left 520 in the remaining cells. I also had to change the "minimum injector pulse width" table. I put 0 in the cells for 0-1000 and left the remaining at the value given in Greg's dvd.

Doing that allowed me to get a 1.00-1.15 reading on the wideband, also allowed my injector pulse width to get down to the 1.5-1.6ms at idle, where as it would only go to 1.9-2.0 before. I still get an overly rich smell (enough to burn eyes after 5 mins of idle) but the smell is different than before. I believe I am heading in the right direction, but if I am not, I hope one of yall can point me in the correct/better route.

I appreciate yalls help so far

[HNK]

Whats your idle timing set at?

ok so in the "injection Boundary" table I added 35 degrees to what was there (520) for a total of 555 in cells from 0-1024, and left 520 in the remaining cells. I also had to change the "minimum injector pulse width" table. I put 0 in the cells for 0-1000 and left the remaining at the value given in Greg's dvd.

Doing that allowed me to get a 1.00-1.15 reading on the wideband, also allowed my injector pulse width to get down to the 1.5-1.6ms at idle, where as it would only go to 1.9-2.0 before. I still get an overly rich smell (enough to burn eyes after 5 mins of idle) but the smell is different than before. I believe I am heading in the right direction, but if I am not, I hope one of yall can point me in the correct/better route.

I appreciate yalls help so far

[sabastian458]

I posted 4 of the idle spark tables in the spread sheet

[sabastian458]

ok, im kinda realy peeved and tired of this car right now. I have have been making slight changes over the last few days. I will log the car, check the histo's and change some more.

So far, like I have posted before, I got my idle Lambda to read in the 1.04-1.15ish range. Driving it will read .93-1.02, gradgually usually it will run in the .98-1.00ish. There is a spot in the 2200-2700 area, in every gear, that will go 1.26+ and then go back to 1.00. Nothing I did would richen that area up. And now today the car kept going into safty mode, almost causes me to get rearend. No reason why it did it. I took the 3rd previous flash and wrote into the ECU and it went back to driving normal for about 5-7 mins, then back into safty mode. No idea why it would do that. I had to back up to the 4th or 5th prior tune to get the car to work, where as those tunes had never given me issues before.

I would like to get a Stock 2005 GTO tune, I dont know if the one in the reposi is truely a stock GTO tune, and just start from nothing again.

Anyone know why the tunes for a 05 GTO and a 05 corvette would be different? I know the VE tables and fueling tables would be, but not the knock sensors and such.

[BBA]

You need to set your idle base/HO and LO timing to a MINIMUM value of 6º to 10º in any cell. Cams generally thrown MAF flow results all over the place and your timing will jump all over to negative values and this will kill idle/starting consistancy. In other words, get rid of ALL negative numbers and make numbers in RPM ranges below your stall/driving RPM's static at some point that actually gives you timing without causing KR. For a radical cam in an LS2 I had to set timing in all cells below 3000 RPM to 30º in order to make the idle and hot startup smooth...just FYI.

[sabastian458]

can you post up a pic of the timing maps for me to look at?

[sabastian458]

ok, after that last attempt at messing with injector boundaries, I had undone all of it and put it back to stock values. I have been cleaning up the VE table still, I cant seem to ever get it to stay where I want it too. And for the life of me I cant figure out why I keep getting a lean section in the 2000-3000 range in any gear. Once every 5 drive cycles or so, it will act correctly and lambda will read .98 and hover arround there, but most all the other time it is 1.25 and higher. No ammount of added airflow changes that.

I think there might be a mechanical issue somewhere, as the car went into safty mode again. I do not know why, it does it randomly. It started with the injector boundary changes, but now it has done so on a tune that does not have any injection boundary changes.