What would cause a weird spike like this in the 1800 rpm range. I am working on tuning my VVE tables in open loop using my wideband and I keep getting this weird spike. It obviously wants fuel there but why? Shouldn't the VE tables be smooth? This is on a turbo 5.3 with a e38 PCM. Also, anyone have a link for some good tips on VVE tuning using a WB? I feel as though I am chasing my tail with this.
Not sure if you got this resolved already or not but look at your transient fueling..its spiking lean on tip-in and its likely showing up on your histo because cell hits required is prolly a little low. Just a thought
Well I ended up switching back to using LTFT's to tune my part throttle areas and It seemed to get a little better but the weird ridge is still there. How is everyone going about filtering out transient conditions while still being able to hit all the decel parts of the VE? I seem to be having a hard time getting the hard decel LTFS close to zero and that's with COT and DFCO disabled. Also, this is all street tuning btw.
Also, can anyone help me out with my cold start issues? The AFR's are going very rich for the first ten seconds causing the truck to almost die. They then will spike lean and then closed loop comes on and the AFR's start to oscillate between 14.7 and very lean until the AFR's seem to settle down. Attached is my current tune file and a log of a rough start. It will start fine once warm. If anyone could point me in the right direction that would be greatly appreciated!
As sated above make sure your hit count is not set too low on whichever PID you are using to make the adjustments. Make sure you are resetting your fuel trims before each logging session. Also, don't cheat out on the variation(not wot) and length of the driving during the logging sessions.
What injectors are you running and did you need to scale them?
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