high fuel trim at 89

[boostmaster]

My high fuel trim is at 89... but when i try to lean out the afc i get knock, whats the deal w/this? i got 550s, walbro 255, clipped 16g, web cams, FMIC, hacked MAF, Safc, datalogger-MMCD. Also my low fuel trims are like 130, i really dont want to mess w/anything because she runs and pulls great and I rarely get knock above 5 in the upper rpm range. Oh, and another thing while im thinking of it, it sems like i get 0 knock every run if my TPS reads around 96% but if I giver her 100% throttle, I start getting knock around a 12 count? Is my car screwed up or what?

thanx,
Blake

 

[psychlow]

When you lean it out, reset your ECU. It's injecting 11% less fuel because that's where it thinks things are kosher. If you reset it, it'll start out at 100%. Then log and watch for knock.

 

[TURFNNSURF]

Your HI fuel trim has NOTHING to do with your WOT pulls and knock. High fuel trim is only affected by closed loop driving above 2500rpm and 45mph. Check your LOW settings on the SAFC between 2500 rpm and 3500 rpm. Lower those settings about 5-10% and drive the car for a while and see if your HI trim moves up toward 100%. With your LOW fuel trim try adding a little 3-5% between 600rpm and 2000rpm, that will help your low trim get back to near 100%.

If you are seeing knock during a WOT pull then ADD some fuel with the SAFC in HI mode in the higher RPMS between 3500rpm and 7000rpm the knock should come down with a little extra fuel.

 

[5150DSM]

I don't see an AFPR in your mod list. With the 255 you are overrunning the stock FPR and the 550's are just making things worse. Your fuel curve is sloppy and non-linear, making tuning at any specific point a bi*** because every change you make just screws up a setting at another RPM point. Get an AFPR, set your base pressure to 43 psi, reset your ECU and then start tuning from there. Good Luck.
Aloha

 

[boostmaster]

Your HI fuel trim has NOTHING to do with your WOT pulls and knock. High fuel trim is only affected by closed loop driving above 2500rpm and 45mph. Check your LOW settings on the SAFC between 2500 rpm and 3500 rpm. Lower those settings about 5-10% and drive the car for a while and see if your HI trim moves up toward 100%. With your LOW fuel trim try adding a little 3-5% between 600rpm and 2000rpm, that will help your low trim get back to near 100%.

If you are seeing knock during a WOT pull then ADD some fuel with the SAFC in HI mode in the higher RPMS between 3500rpm and 7000rpm the knock should come down with a little extra fuel.

i did this and my mid and high trims are 100 but my low fuel trim reads like 139.8. and i dont know if it had anything to do w/the changes I made but the power seems to come on more smoothly. Just dont know another way i can get my low trim to 100, will it hurt to be this lean?

 

[DevilSperm]

mine stays at 139...its not really going to hurt anything IMO...when i try to richen it, it doesnt move much anyway....i have yet to see a 1g around here that doesnt have 139 for a low trim

 

[4sfead]

mine stays at 139...its not really going to hurt anything IMO...when i try to richen it, it doesnt move much anyway....i have yet to see a 1g around here that doesnt have 139 for a low trim

I just turn the knob on my Translator and the low trim on my 1g stays right around 100. But I agree with you that the low really doesnt matter much IMO. Even the 89 high trim is good to me.