Fuel Trim Weirdness
02-27-2006, 11:13 AM
#1
Fuel Trim Weirdness Hello Everyone,
Here is the story. I'm working on my OLSD tune and am having this weird problem where my car will drive alright for the first 5-10 mins after a PCM calibration, but then it'll start to stall once I push in the clutch and let off the gas, once it stalls, its really hard to start, and once i get it to start, when I come back to another stop or let off the gas it'll stall again, until I do another PCM calibration then it'll run fine again.
I was logging, and it appears that when i'm having this stalling issue, my PCM seems to be keeping me in the Fuel Trim cell 22 even if my throttle is at 0 and clutch in. I don't understand it! My VE table at idle is dead on, and I'm still working on the rest of my VE table at the moment.
I've got everything set up properly to be in SD mode, the computer isn't reading anything from the O2 sensors, MAF sensor unplugged, I've got my RAF dialed in, Underspeed/Overspeed tables fixed, my throttle follower/cracker tables fixed, VE table at idle dialed in perfectly (AFR 14.63-14.67 when warmed up), Vehicle gets up to about 190-200 degrees. My TPS also doesn't come down all the way to 0%, I have re-calibrated the TPS, and also adjusted b0108 to .8 to adjust for this so the PCM will know that i will be at idle conditions when this happens. Only thing is my IAC counts seem to be a little off, what step count should I be seeing at Idle? I will adjust my set screw to get me there and see if that helps.
If anyone knows why my vehicle likes to stick in Fuel Trim cell 22 which causes my car to choke out, please let me know! I have log files, and my tune file via EFILive. I'm getting a lot of help from TAQuickness and Andrew Jensen, but we just can't seem to crack that weirdness! If anyone has any suggestions let me know!! Also, if anyone wants to see my tune and log file just shoot me an IM with your e-mail address!!
Thanks!
Adrian
Here is the story. I'm working on my OLSD tune and am having this weird problem where my car will drive alright for the first 5-10 mins after a PCM calibration, but then it'll start to stall once I push in the clutch and let off the gas, once it stalls, its really hard to start, and once i get it to start, when I come back to another stop or let off the gas it'll stall again, until I do another PCM calibration then it'll run fine again.
I was logging, and it appears that when i'm having this stalling issue, my PCM seems to be keeping me in the Fuel Trim cell 22 even if my throttle is at 0 and clutch in. I don't understand it! My VE table at idle is dead on, and I'm still working on the rest of my VE table at the moment.
I've got everything set up properly to be in SD mode, the computer isn't reading anything from the O2 sensors, MAF sensor unplugged, I've got my RAF dialed in, Underspeed/Overspeed tables fixed, my throttle follower/cracker tables fixed, VE table at idle dialed in perfectly (AFR 14.63-14.67 when warmed up), Vehicle gets up to about 190-200 degrees. My TPS also doesn't come down all the way to 0%, I have re-calibrated the TPS, and also adjusted b0108 to .8 to adjust for this so the PCM will know that i will be at idle conditions when this happens. Only thing is my IAC counts seem to be a little off, what step count should I be seeing at Idle? I will adjust my set screw to get me there and see if that helps.
If anyone knows why my vehicle likes to stick in Fuel Trim cell 22 which causes my car to choke out, please let me know! I have log files, and my tune file via EFILive. I'm getting a lot of help from TAQuickness and Andrew Jensen, but we just can't seem to crack that weirdness! If anyone has any suggestions let me know!! Also, if anyone wants to see my tune and log file just shoot me an IM with your e-mail address!!
Thanks!
Adrian
02-28-2006, 09:18 PM
#5
Yea, I've already gone through and checked all of that stuff. I even replaced all of my intake seals, so I doubt that it's anything with that. If it was a leak of any sort it would happen the second I drove my car, but it takes a good 10 mins of driving before I have stalling issues. Then once I do a PCM calibration again, it'll run fine for another 10 mins then start stalling. I believe it has something to do with the idle learning controls, but I just can't narrow it down!! I've adjusted all of my learning tables and it didn't affect any of the stalling problems. I'm considering now just to zero out all my idle learning tables and see if that helps. I dunno, I just don't get it and I'm just losing my mind over getting this problem solved. If anyone else has anymore suggestions let me know!!! I feel like there is some setting that I'm over looking that will fix my problem. I have tune files and log files avaliable, just send me an e-mail at haans249@gmail.com
Best Regards!
Adrian
Best Regards!
Adrian
03-01-2006, 04:20 AM
#6
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iac at idle is generally around 30 and mid to high 100's while driving.
Doesnt really matter too much as long as you dont max it out, 255 i think, or thereabouts.
Does it run fine with stock closed loop tune? That will eliminate all causes other than the tune.
Doesnt really matter too much as long as you dont max it out, 255 i think, or thereabouts.
Does it run fine with stock closed loop tune? That will eliminate all causes other than the tune.
03-01-2006, 04:32 AM
#7
TECH Resident
Originally Posted by Haans249
Hello Everyone,
Here is the story. I'm working on my OLSD tune and am having this weird problem where my car will drive alright for the first 5-10 mins after a PCM calibration, but then it'll start to stall once I push in the clutch and let off the gas, once it stalls, its really hard to start, and once i get it to start, when I come back to another stop or let off the gas it'll stall again, until I do another PCM calibration then it'll run fine again.
I was logging, and it appears that when i'm having this stalling issue, my PCM seems to be keeping me in the Fuel Trim cell 22 even if my throttle is at 0 and clutch in. I don't understand it! My VE table at idle is dead on, and I'm still working on the rest of my VE table at the moment.
I've got everything set up properly to be in SD mode, the computer isn't reading anything from the O2 sensors, MAF sensor unplugged, I've got my RAF dialed in, Underspeed/Overspeed tables fixed, my throttle follower/cracker tables fixed, VE table at idle dialed in perfectly (AFR 14.63-14.67 when warmed up), Vehicle gets up to about 190-200 degrees. My TPS also doesn't come down all the way to 0%, I have re-calibrated the TPS, and also adjusted b0108 to .8 to adjust for this so the PCM will know that i will be at idle conditions when this happens. Only thing is my IAC counts seem to be a little off, what step count should I be seeing at Idle? I will adjust my set screw to get me there and see if that helps.
If anyone knows why my vehicle likes to stick in Fuel Trim cell 22 which causes my car to choke out, please let me know! I have log files, and my tune file via EFILive. I'm getting a lot of help from TAQuickness and Andrew Jensen, but we just can't seem to crack that weirdness! If anyone has any suggestions let me know!! Also, if anyone wants to see my tune and log file just shoot me an IM with your e-mail address!!
Thanks!
Adrian
Here is the story. I'm working on my OLSD tune and am having this weird problem where my car will drive alright for the first 5-10 mins after a PCM calibration, but then it'll start to stall once I push in the clutch and let off the gas, once it stalls, its really hard to start, and once i get it to start, when I come back to another stop or let off the gas it'll stall again, until I do another PCM calibration then it'll run fine again.
I was logging, and it appears that when i'm having this stalling issue, my PCM seems to be keeping me in the Fuel Trim cell 22 even if my throttle is at 0 and clutch in. I don't understand it! My VE table at idle is dead on, and I'm still working on the rest of my VE table at the moment.
I've got everything set up properly to be in SD mode, the computer isn't reading anything from the O2 sensors, MAF sensor unplugged, I've got my RAF dialed in, Underspeed/Overspeed tables fixed, my throttle follower/cracker tables fixed, VE table at idle dialed in perfectly (AFR 14.63-14.67 when warmed up), Vehicle gets up to about 190-200 degrees. My TPS also doesn't come down all the way to 0%, I have re-calibrated the TPS, and also adjusted b0108 to .8 to adjust for this so the PCM will know that i will be at idle conditions when this happens. Only thing is my IAC counts seem to be a little off, what step count should I be seeing at Idle? I will adjust my set screw to get me there and see if that helps.
If anyone knows why my vehicle likes to stick in Fuel Trim cell 22 which causes my car to choke out, please let me know! I have log files, and my tune file via EFILive. I'm getting a lot of help from TAQuickness and Andrew Jensen, but we just can't seem to crack that weirdness! If anyone has any suggestions let me know!! Also, if anyone wants to see my tune and log file just shoot me an IM with your e-mail address!!
Thanks!
Adrian
Trending Topics
03-01-2006, 08:29 AM
#9
I guess I left a HUGE part of this whole mix out....my engine isn't stock....hhahaha
FAST 90/90, EDC Cam
, 42lb svo's, ARE Stage 3 heads, UD pulley, edelbrock headers, ORY, Volant CAI, LC-1 Wideband.
My O2's aren't reading anything, and I guess my Idle air control counts are pretty good then...
Thanks!
Adrian
FAST 90/90, EDC Cam
, 42lb svo's, ARE Stage 3 heads, UD pulley, edelbrock headers, ORY, Volant CAI, LC-1 Wideband.My O2's aren't reading anything, and I guess my Idle air control counts are pretty good then...
Thanks!
Adrian
