90AWDTalon
20+ Year Contributor
- 877
- 3
- Jan 5, 2003
-
Everett,
Washington
First off my profile is up to date.
This issue has been going on for a while now, but originally I didn't care, I just did what I had to to make every thing work. The issue I'm talking about is I seem to have to set my fuel tables really rich to get my desired afr. Late last year I decided to calibrate my MAFT. I couldn't get the MAFT to send a high enough airflow signal to keep from leaning out, so I had to set my target afr richer than my actual afr. No matter what I did I couldn't get the MAFT to go above 46 LB/MIN, whether its more boosts or adjusting the MAFT settings. So I thought maybe it was because I had the old 1.3 version of the MAFT. So I ordered a new 2.??? version chip from fullthrottle speed, same story no changes.
Fast forward to early this year. Thinking something must be wrong with the maf sensor( 3 inch LT1 ), I swapped it out for a 3.5 inch LS1 maf sensor. Along with some other changes, BC 272 cams, removed balance shafts, and swapped press bent 3" exhaust for mandrel bent 3" exhaust. Until recently I just had a ruff tune that allowed me to drive it around with out issues. The weather has gotten nicer so I have been retuning the car. I started out at my low boost setting( 20psi ), I got the maft calibrated to withing +/- 1%. I thought I had solved my problem, but in the back of my mind I wasn't sure because I was right at 46 LB/MIN at the top of the rev range. So I started turning up the boost, as I did this airflow stayed maxed out at 46 LB/MIN, it would max out earlier in the rev range than lower boost. But I was going leaner and leaner the more I upped the boost. At 27psi I was still at 46 LB/MIN of airflow, my target AFR is 11.0:1, I was at 12.5:1.
So I did an experiment. I upped my base fuel pressure 10% and leaned my base settings in the MAFT 10%. The result was still the same 46 LB/MIN but now my afr was 11.6:1.
Any one have any idea of what might be going on? I have plenty fuel. I'll attach a copy of my eprom bin and TunerPro RT ecu file encase the problem is something in the code. Its set for my fic 950 injectors, pk elimination, airflow cap removed, extended maps, no fuel cut, no octane map, custom fuel and timing maps, 5800rpm studder, 8000rpm redline, 850rpm idle, and boost gauge = knock guage. Maybe a couple of other things I'm forgetting, I've been running the same basic chip for 3+ years.
http://home.comcast.net/~talonawd/E931_32k_3addedstudder.ecu
http://home.comcast.net/~talonawd/studder5800ver8.1.bin
This issue has been going on for a while now, but originally I didn't care, I just did what I had to to make every thing work. The issue I'm talking about is I seem to have to set my fuel tables really rich to get my desired afr. Late last year I decided to calibrate my MAFT. I couldn't get the MAFT to send a high enough airflow signal to keep from leaning out, so I had to set my target afr richer than my actual afr. No matter what I did I couldn't get the MAFT to go above 46 LB/MIN, whether its more boosts or adjusting the MAFT settings. So I thought maybe it was because I had the old 1.3 version of the MAFT. So I ordered a new 2.??? version chip from fullthrottle speed, same story no changes.
Fast forward to early this year. Thinking something must be wrong with the maf sensor( 3 inch LT1 ), I swapped it out for a 3.5 inch LS1 maf sensor. Along with some other changes, BC 272 cams, removed balance shafts, and swapped press bent 3" exhaust for mandrel bent 3" exhaust. Until recently I just had a ruff tune that allowed me to drive it around with out issues. The weather has gotten nicer so I have been retuning the car. I started out at my low boost setting( 20psi ), I got the maft calibrated to withing +/- 1%. I thought I had solved my problem, but in the back of my mind I wasn't sure because I was right at 46 LB/MIN at the top of the rev range. So I started turning up the boost, as I did this airflow stayed maxed out at 46 LB/MIN, it would max out earlier in the rev range than lower boost. But I was going leaner and leaner the more I upped the boost. At 27psi I was still at 46 LB/MIN of airflow, my target AFR is 11.0:1, I was at 12.5:1.
So I did an experiment. I upped my base fuel pressure 10% and leaned my base settings in the MAFT 10%. The result was still the same 46 LB/MIN but now my afr was 11.6:1.
Any one have any idea of what might be going on? I have plenty fuel. I'll attach a copy of my eprom bin and TunerPro RT ecu file encase the problem is something in the code. Its set for my fic 950 injectors, pk elimination, airflow cap removed, extended maps, no fuel cut, no octane map, custom fuel and timing maps, 5800rpm studder, 8000rpm redline, 850rpm idle, and boost gauge = knock guage. Maybe a couple of other things I'm forgetting, I've been running the same basic chip for 3+ years.
http://home.comcast.net/~talonawd/E931_32k_3addedstudder.ecu
http://home.comcast.net/~talonawd/studder5800ver8.1.bin
