I've searched and haven't found my specific situation so i'm hoping u pro tuners can help me out here...
Basics Powerlab gt35r - Haltech ecu
Last night when I was running the car noticed that my air/fuel is starting to slowly climb under WOT. I thought it might've been because of the cold weather (68' last night and my car was tuned in the hot *** afternoon)..
Drove the car around again today in the afternoon and it was still climbing... Starts from about 11.5 at like 3krpms and then as the rpms rise so does the a/f gauge.. Read out to 12.6! Of course the car pulls like a **** but this is crazy lean IMO.. Can anyone tell me why all the sudden it would start doing this? Before it was pretty spot on at 11.5-11.8 all throughout not sure why its starting to steadily climb now under wot... Aside from that everything else seems to be fine.. Boost holds steady at 8lbs all the way and the car pulls hard... Can't seem to figure out why now it seems to be runnin more lean.. Any help would be appreciated.. If u need more info lemme know what else i can provide. Thanks

 

It means your compensation tables are off. Take it back to your tuner for and adjustment.

 

Whoa, hella fast reply, thanks man!
Just wondering how can the tune just fall off? Shouldn't it hold steady? Would kinda suck to have to keep going back to my tuner everytime this happens...

 

depending on the tables, the tuner just guesses as to the compensation values. they wont be spot on until you can tune in varying temps.

 

True but now its back to the normal temp for when I got my tune and my a/f is still climbing up... Wasn't doing this before til last night.. Can't seem to figure out why it just started to climb, thought it was cuz of the weather last night but now it's the afternoon n still rising.

 

Tuner told me to troubleshoot the fuel system first before I get it re-checked by him.. He suggested something might be wrong with the fuel system or pump for me to be losing fuel pressure under load as the rpms increase... Hope its somethin simple.. When i drove it earlier today it still pulled hard n held boost steady the whole way..

 

Do you have a fuel pressure gauge, and how much gas is in the tank? Assuming you have full tank of gas to eliminate that, and fuel pressure gauge is reading proper - then it is the tune.

 

No, no fuel pressure gauge... Prolly sumthin I wanna invest in soon.. I had half a tank but I didnt think that would be an issue... I've ran less than half a tank at WOT n never had this problem... Just trying to figure out what everyone means "by the tune".. Is it possible that the tune can just start falling out or sumthin? Gonna have a buddy check to make sure my fuel pump is ok n looks good n then fill up n see if that changes.... I'd think it would kinda suck if I have to stay at over half a tank to keep from leaning out. Now that I think about it when I got the tune done I was at about half a tank also...

 

At 1/2 tank, that should not be a problem... but fill it up and see what happens.

"the tune" means your tune is not properly compensating for something. A tuner does his best to match real world conditions on the dyno, or at least account for them in compensation tables. If the compensation tables (such as fuel correction based on intake air temperature) are not properly calibrated, then anytime the temperature changes the tune will be off.

 

+1 on that.

I had tuned my car early in the spring, and now that the temperatures have gone up, adjustments on the IAT had to me made.

Car has same a/f no matter what the outside conditions are.


I also adjusted the IAT compensation for when the car sits and the IAT sensor gets heat soaked. It was an issue before, but not any more.

 

Well after goin back to my tuner n checkin out the number on his dyno and then goin out n datalogging to read what my a/f is i think its my prosport gauge thats f'd up... I read no higher than 11.5's datalogging on the haltech and i read no higher than 11.5 on the dyno when i checked it out... we re-calibrated the gauge n its still reading high... not sure what to do cuz its jus not readin what my haltech reads.. kinda stuck on this issue cuz i'd really like to have the haltech display gauge (i got the dual wideband for it) but no display gauge to give me an ACCURATE reading... my current gauge is just fubar'd...