So I have an 05 LGT Limited 5-speedMT. I just started tuning not too long ago(via COBB tuner) because I absolutely love DIYing and saving money is a big plus. Starting off and making the car run smoothly wasn't that much of an issue but the more I get into refining stuff the more barriers I hit. I wanted to start off with my build list before I explain my main issue:
Bottom end:
Manley H-TUFF rods
JE Pistons 99.75 8.5:1 comp ratio
King bearings(rod+main)
Brand new STI Nitrated Crank("430")
Other relevant mods/maintenance:
DW 1000cc injectors w/ 07-09 top feed rails
AEM 340lph fuel pump
Tomei Type L FPR
Kinugawa IWG actuator(14psi spring)
Grimmspeed EBCS
DIY tgv deletes(fully gutted)
VF52
Heads resurfaced, vac tested, and had 1 exh valve job done.
Okay now to the issues I'm having which I have tried looking up but had no luck. During normal driving with the AC off, I have the AFR set up to where I like it. The issue is when I have the AC on, especially at idle, AFR is extremely rich. I don't have a WBO2 sensor, which is on the list, but the AFR O2 sensor reads 11 at idle and the highest I'm seeing is 12-13. My question is why exactly is it dumping fuel with the AC on? Another question I have is, what else would cause boost to kick in during normal driving? My wastegate Duty cycle is almost zeroed out and I'm still seeing 2-6psi of boost at around 20-30% throttle. is I will have pics of some of the tables attached below
The last issue I have that probably isn't tuning-related, is the infamous 2-3k rpm stumble. Maybe there is something I missed but I've tried all the methods that I've found on these forums to negate it but had no luck. Those methods are:
- Reroute AFR vacuum and Tee'd off the BPV vacuum
- Different Fuel Pressure Regulator
- Richen the loads for that rpm range(13.5-13.9 afr)
- Raised the Fuel injector Latency(0.85ms to 1ms, this actually made it stumble a bit less but that's the best it gets.)
- BUILT ENGINE! (this wasn't why I built the engine though haha)
NOTE: CL to OL Delays are zeroed out
P.S. I feel like my ignition seems extremely low based on looking at other peoples and stock vs cobb stg2. Any higher and it picks up knock.