Im assuming that getting a better tuner would help but i finally got a wideband installed and have a predator tuner. i had the performance tune in and it was showing too lean most of the time while driving and was jumping all over the place (seemed to run ok though...) so i put the stock tune back in and adjusted the inj slope to add some fuel (5% and added 5% in PE) which evened things out a bit but still wants to run in the 15's unless i get on it. Is this normal or should i still add fuel? most of the widebands on other ppls cars ive seen run right in the middle and when you get on it slowly richen up a little mine does not however it jumps around alot... any suggestions?

 

Have you verified that the wideband readings are accurate? If the car is in closed loop, you should see a consistent 14.4-14.9 on your display.

 

I tried to richen it some more and put the inj slope to 10% and made the pe +8 and i can only get the wideband to show under 14 for a short time or when revving but no matter what it wants to be around 15-16 at idle :o\

 

15 isnt to high at idle

 

Don't take this the wrong way, I am trying to help. I'm not sure you yet have a grasp on what you are changing. Put the car back to stock and do some reading as to what you are changing. Understand that what you are seeing at cruise is the result of closed loop control. YOU do not have control of cruise AFR through any of the routes that you have taken.

 

Very well said^^^.

 

Im not taking it the wrong way... i am just looking for some pointers/info i just got a wideband and i have seen them in other cars and it not near as erratic on there setup... ok so here is what i have... i have been trying to tune the car with a predator (first mistake) for awile and i had it at the dyno shop to get the afr and dyno numbers. before i got the wideband it was at 13.2 afr WOT. they left the inj slope unchanged and added +3 to PE I have seen that 12.9 was was most ppl shoot for for a WOT afr. so when i got the wideband i tryed to get it around 12.9. from what ive seen you are supposed to adjust inj. slope first to try to get the normal driving fuel trims to settle at 0.00 or negative and then see where WOT is and adjust pe for WOT and that inj. slope can affect WOT as well. here is my question what is it that the inj slope changes exactly(should i even mess with it with the mods listed in sig) and should i only worry about WOT afr and use PE. also my car is consistantly at around 15 afr (closer to 15.5-16 most of the time) but goes right where i want it when its WOT.. is this normal. Thanks for the responses and i would highly appreciate any help i can get and yes i am kind of newb to tunning but not a newb to cars

 

Changing the injector scale is considered an old-school way to tune since that is a table that we KNOW is correct for the getgo, but it's the only real approach that you can take, and it will get the job done for your setup.

You want to adjust it until you can log while out driving and see all trims outside of idle be slightly negative. You want them negative. If they are positive, they will lock in positive at WOT and add extra fuel, skewing your mixture. Once you adjust this table, it will skew your WOT AFR, so once you get the trims right you will have to go back and redo PE. Since you will be lowering the injector table to move your trims negative, the side effect at WOT will be that your setup will go richer than you want afterwards, so you don't have to worry about it being lean after changing the slope if it's at 12.9 or so now, unless you are increasing the slope in some areas. I hope that makes sense.

oh yeah, your AFR at cruise is a result of the trims trying to maintain stoich. This is not really something you can adjust with the predator, and not something to be concerned about either unless you are experienceing an issue like stumbling.

 

ok so if i get what you are saying.. as long as the car seems to run fine and it hitting a good a/f ratio at WOT and the computer is showing no positive fuel trims i should not worry.. and the only way to control some of what is goin on with the a/f at idle or cruising i will need a different tuner. if so i was afraid that was the case and it just bothers me that when i start the car (a.i.r is disabled) a/f readings look normal and are on the safe side of stioch 13-14.7 but as soon as it starts warming up and uses the maf (as mentioned in sig i have ported tb lid and descreened maf) the a/f is now always on the lean side (14.8-16)except for WOT... even if the computer says that fuel trims are not positive. so if a better tuner is what i need then i guess i better start looking.. what do you guys think?

 

fyi the settings it is at right now with no positive fuel trims is -10% on inj slope with the predator and 0 PE changed and runs at about 12.8 WOT a/f and as metioned above seems a little lean on norm driving 15-16 a/f does that sound right..

 

Why do you think there is a problem with the cruise AFR? If it's ACTUALLY at 15-16 driving, then that is unusual, but if it cruises fine there, you know mileage is good like that, what's the problem Like I said, if it's bucking or something then I understand, but if it drives fine....

how old are your O2s? If they are pretty aged, you may see some difference in AFR at cruise with fresh ones, but like I said, numbers notwithstanding, how does it drive?

 

well when i really get on it or am driving aggressive it seems to drive just fine but just normal driving it seems a little off (i.e. yes a little bucking or jittering nothing real bad but since i drive it all the time i notice it and thats why i was trying to correct the a/f at cruise since its showing on the lean side with a wideband and i had new denso 02's put in just about 3kmiles ago or so the car has 68k on it. if what im seeing is normal then ok.. but seeing as the wideband shows im running lean 90% of the time im a bit concerned and im bad about wanting everything just right..

 

OK... so something has been up with my car not running correctly leading me to believe its a tune issue... although im sure the MAF readings are off due to header/intake mods this weekend i found a key problem. i have had a little tick noise for some time thats gotten worse since the header install(done by the dyno shop)so this weekend i finished pulling the air and egr systems off and figured hey why not check the plugs and headers for leaks... I got better plugs and just replaced them while i was in there and found that #2 had a slight leak(tightened just fine with the new plug and #7 was almost all the way out!! I crossed my fingers and put the new plug in but it would not snug more then finger tight. the last time the plugs were touched was by the shop that did the headers. needless to say i am pretty pissed and even though its a good excuse to get new heads/cam i really wasnt ready for it yet... thanks to those who gave me help on the tuning and im sure after a new tuner and possibly heads/cam ill need your help again thank you

 

use some heavy grease on a tap (to catch trimmings) and SLOWLY thread it in just as far as you have to

 

frost.. thats exactly what i want to do however im afraid of tapping it at the wrong angle/depth since there is NO room to work on that plug.. its better since i have headers and have removed the air but you just cant see what your doing with that plug location.. and im afraid of leaving shavings in the chamber(you said to use heavy grease but even then i would be concerned). Ive done that before on another car with alum heads that I accually stripped out lol but i could get to it very easily. even though i know that it wont hold for a long time what i ended up having to do was use jbweld at the top of the threads(so it was still grounded) to hold it in until i could have the hole repaired or new heads put on. If you have any good suggestions on any other fixes or tips on tapping that hole without damaging anything id appreciate it! So far.. it has held up no more ticking and it runs like a champ i romped on it a few times and its been about 3 weeks. but its only a bandaid fix. one thing though related to the original topic... Now that my plugs are tight and exhaust is all welded up (no leaks) my wideband still is showing its running lean on norm idle/driving -WOT i can get wherever i want it 12.9-13.1. now i experimented a little after what Frost said and put all settings back to default to see if the a/f changed.. and as he said the car ran in the same range 14.8-15.8 usually on steady 2-2.5krpm driving and 15.6-16.5 on idle no matter how much i changed the inj slope. but what it did change was the a/f at WOT and thats it. I could use -10 (richer) inj slope and the comp does not read +ltft and the wot was real close to my target or i could say use -5 on the inj slope setting and add PE 3-4% and see the same results or leave the inj slope alone and use +5-8% PE and also see the same a/f activity. So its obvious that my tuner just cant change what i need it to. The car i believe is running lean even though the car thinks its fine when the settings are determined by maf readings. At WOT i can get it right where i want it. if there is anything i can do to help get the numbers where they should be or what tuner to get that i can get alot of help with and has alot of control like efi or HP id like some opinions - thanks <-- me beating a dead issue lol but seriously any suggestions are appreciated! Ohh and Frost- my ride looks identical to yours except the wheels(good taste) and is not near as fast im sure as im only in the 12's