Ok so I am learning how to tune with my current setup. I have 310cc injectors i figured out a .14470 injector constant that I got from PJ's formula. I have a stock 2001 LD9 bottom end and a ported and polished 97 head and some cams with slightly smaller lift than HO but the same duration. I cant get it to idle decent while getting the top end right. When I idle around 13.4 afr with a constant of .12640 it leans out up top and changing VE offset hasnt helped. I went up to 32 percent which seems crazy for n/a. When I change the constant to pj's formula it will idle pig rich in the 10s but got into the 13s up top. My target AFR was 13.7 but the car is happier feeling in the high 12s so I might change that. I should add Im using shifted's histograms for the VE tables. Im really just experimenting and learning but what can I do to make the top end and the idle both happy? Its frustrating. Ive decided to start with a fresh tune so any advice would be great. Thanks in advance for the help.
Edited 1 time(s). Last edited Monday, August 02, 2010 8:21 PM
Now im just really frustrated. I started over with a fresh tune. I had to bump the VE offset to 24 to achieve proper AFR for the PE VE table and the high rpm and low rpm VE tables are great. But the car idles at 10.6 afr, I have lowered the correct cells in the idle table as low as possible and raised the idle some and it still idles like that. What am I doing wrong?
Zs Z wrote:Now im just really frustrated. I started over with a fresh tune. I had to bump the VE offset to 24 to achieve proper AFR for the PE VE table and the high rpm and low rpm VE tables are great. But the car idles at 10.6 afr, I have lowered the correct cells in the idle table as low as possible and raised the idle some and it still idles like that. What am I doing wrong?
I know exactly what you are doing wrong... When you bumped up your VE Offset multiplier, you did subtract that same amount out of the tables before making the adjustments... Are you only raising the offset, and not tuning the VE tables based by cell? If so, you are not tuning, you are just throwing fuel at it.
Lets say you have a VE offset of 10, but you need to go above 110 VE. Lets say we change the offset to 30. What that does is raises ALL the values in ALL the VE tables. When you make an adjustment to the offset, you must close ALL the VE tables 1st, change the offset, then SAVE immediatly. Next you go into EACH VE table and subtract the amount you added to the offset. Then make changes to the appropriate cells. I have seen many people do this time and time again..... You have to pay attention to your numbers... Go and compare your current tune and your old tune. I bet I am right,.... Also, if you were to subtract from the VE offset, you must add the amount you subtracted to the tables..
P&P Tuning
420.5whp / 359.8wtq
I get what you are saying and I will definitely do it that way, it seems much easier than what i did. I drove around after upping the VE offset and use the histograms to knock the values that were too high back down to the proper values for my target AFR, i did this twice. Now my Idle VE is set at 24 in the cells and the low VE tables have the same values where it overlaps, this is as low as it lets me go and it still idles at 10.6. Are you saying that even though I subtracted from the individual cells that possibly my ecu is freaking out because I didnt set the values back from the entire offset?
Edited 1 time(s). Last edited Tuesday, August 03, 2010 10:14 AM
I can't follow you exactly, but do what Ryan said.
If your total VE offset is 24%, it will automatically bump up all values in all charts by 24%. So you can either do one of two things:
After bumping up 24%, copy and past the values into Excel, subratact out 24% from every value using an equation, then past it back into your idle table.
Or just copy all the values from your stock tune in your idle table and paste it back into your new tune idle table.
What you're trying to accomplish is making your Idle VE table look just as it did stock - if you have the correct injector constant mathematically it should work out.
Try this and post back.
Also remember, if your car is cold it will stay in open loop and only be reading from the table values and not the O2 sensor or fuel trims - let it warm up to go into closed loop then start logging your idle data and see how your table looks - this should make it work.
That's somthing I didn't think of. I Have been logging in open loop since I am tuning the VE tables. I will have to check it once I enable the closed loop again.
heavyclutch wrote:I can't follow you exactly, but do what Ryan said.
If your total VE offset is 24%, it will automatically bump up all values in all charts by 24%. So you can either do one of two things:
After bumping up 24%, copy and past the values into Excel, subratact out 24% from every value using an equation, then past it back into your idle table.
Or just copy all the values from your stock tune in your idle table and paste it back into your new tune idle table.
What you're trying to accomplish is making your Idle VE table look just as it did stock - if you have the correct injector constant mathematically it should work out.
Try this and post back.
Also remember, if your car is cold it will stay in open loop and only be reading from the table values and not the O2 sensor or fuel trims - let it warm up to go into closed loop then start logging your idle data and see how your table looks - this should make it work.
No need to do all that. All he needs to do is go to the Idle file highlight the whole file and then add -24%, that will actually substract the 24% he added when he upped the VE offset.
One thing what was your stock VE offset? 10%? If so and you are now at 24% VE offset you only need to lower it 14%.
FU Tuning
^^^agreed.
when you increase your VE offset, all the tables are raised by that same amount.
go from 20%-30%, the tables will all increase by 10.
go into your idle table, and decrease by the same amount you increase.. so continuning the above exmaple, you would want to add -10% to the idle tables.
you're going to be running off the VE map and fuel trims will be off, so you are going to definitely idle richer, but it should be closer to your desired PE AFR... roughly 13:1
good luck.
^ ^ ^ damn - I didn't know that shortcut above. I always mess with Excel when bumping the offset.
Cool thanks, I can't wait until tomorrow so I can try it.
heavyclutch wrote:^ ^ ^ damn - I didn't know that shortcut above. I always mess with Excel when bumping the offset.
I did not either until real recently, thanks to Ryan.
FU Tuning
Screaming for Mercy!! wrote:heavyclutch wrote:^ ^ ^ damn - I didn't know that shortcut above. I always mess with Excel when bumping the offset.
I did not either until real recently, thanks to Ryan.
it's not even a burried command - thanks for waking me up.
That fixed the idle problem for the most part, thanks for the advice. Now my next big thing to tackle is LC-1 wideband voltage offset. I was just reading about this. I have not hooked the actual guage up yet just been reading AFRs through HP tuners. Is there a usual amount the LC-1 is off and how do I adjust for it?
