Kaneman

iTrader: (5)

Ok I am tuning my VE table using the Wideband method from the HP Tuners help area. Everything is working out real well except one small thing and nothing I do seems to change the AFR.

I have one cell 800rpm 35kpa this is where my 900rpm idle falls into. I am running rich and the afr error keeps telling me to subtract more out of this feild but no matter what I put the number at it does not change the afr.

Now here is the funny thing I have my AC idle set to 925 so when I turn the AC on it falls into cell 40kpa and AFR is perfect.

I could raise my idel to 925rpm and the problem may go away but I really want to figure this issue out.

Any ideas?

Thanks,

Kane

2000WS6ICK

iTrader: (2)

I may be wrong but your power enrichment eq ratio vs rpm changes how much fuel your getting and will change your afr.

jimmyblue

iTrader: (11)

Look at the actual injector pulse width and see if
it is the same as the min limit value.

If you use the bidirectional controls to force a
particular AFR, does it follow that or stay "stuck"?

Kaneman

iTrader: (5)

That is only when you go into PE and I am just talking idle. PE table is a multiplier that does affect AFR.

Kane

Kaneman

iTrader: (5)

Ok I have tried everything, messing with the VE tables a million different ways and changing the injector offset %.

Here is what is in the car:

408 8 3/4 compression
Cam 220 224 581 581 114 lsa
Injectors Racetronix 79lb

I am tuning the car SD OL with my wideband. Once the car is warm AFR is 12.0-12.5 at idle. When the car is cold idle is at 14.7. If I adjust the injector offset I can get the AFR to rise to 17 or 18 and the kpa is at 45 but as soon as I get the car close to 35kpa it goes right to 12.0-12.5. I noticed that my injector pulse does not go any lower then 2.0 no matter what is in the offset too. If the AFR will adjust when it is cold I would think I could lean it out when it is warm?

Just a thought if I raise the timing at idle does that lean it out?

I have tried everything I can think of so if anyone has some ideas please help. I am attaching my basic tune and a scan for that tune. The car runs pretty good except for that damn rich idle.

Thanks,

Kane

Frost

iTrader: (45)

your minimum and short pulse tables are still stock...


give this one a quick try and see if it moves in the right direction

Kaneman

iTrader: (5)

I will give this a shot today. When are you supposed to change the offset table? I have some people telling me to change this table and then re-adjust the VE table.

Thanks for the help,

Kane

Frost

iTrader: (45)

doesn't much matter what is in most of the other tables if the short pulse tables are keeping the minimum pulse width too high by adding back to it...

Frost

iTrader: (45)

how was it?

Kaneman

iTrader: (5)

I have not had a chance to stick the tune in yet. I will let you know the results as soon as I have a chance to upload it.

Thanks again for the help,

Kane

Kaneman

iTrader: (5)

Ok this did mae a difference and at idle the AFR is at 16 or so. Now I tried to adjust the AFR in the VE table but it caused one sell to be crazy high without much change.

As I kept adjusting a few things I can not get this thing to settle at 14.7 it is either 16.x or 12.x. Here are a couple of more log files.

Where is the best place to adjust the settings at?

Thanks for all the help this thing has been driving me crazy.

Kane

Frost

iTrader: (45)

your minimum pulse appears to be at a workable level now looking at your logs.

Also, I hope you aren't tuning based off of those logs... You are in OL but you have not reset your LTFT's and they are intermittently swinging up and down based on their previously learned values. The *FIRST* thing to do whenever logging OL is to reset fuel trims in the scanner. This has bitten almost everyone at one point or another. If you have been tuning this way, you will have some fairly decent error built in to your VE.

I bet if you put the car in CL it will find a nice 14.7 idle, which will prove that you can too through VE tuning.

Kaneman

iTrader: (5)

Do LTFT still learn even though they are disabled?

Frost

iTrader: (45)

No, they are just applied at their previous value in their previous positions.

Sunny

Thanks for the useful information.

Do you need to reset the long term fuel trims just before disabling them and MAF?

Frost

iTrader: (45)

No, but do it immediately after disabling them and flashing the PCM before you scan for any data that you will make VE changes with. It's in the scanner>Displays>VCM Controls>Fuel&Spark

Kurtomac

iTrader: (5)

when you flash a tune...doenst that reset all the trims ie idle trims, fuel trims etc

Frost

iTrader: (45)

For HPT, if a write-entire is done it will, not the 20 second write-cal which just updates data...

Kaneman

iTrader: (5)

Frost you were totally right once I re-enabled LTFT and enabled closed loop everything fell right into place. I need to do some minor adjustments to the VE table because LTFT's are adding fuel but so far so good.

Should I tune the VE a little more in SD mode and once things are inline re-enable the MAF? I was thinking then do a MAF tune?

I want to thank you a bunch for the help now I am going to put some miles on the car so it can continue learning.

Kane

Frost

iTrader: (45)

MAF on a turbo car? I'd move the car over to a 2 or 3 bar MAP sensor and OS. That 40X" engine will max out a MAF by 5psi-ish...