Hey all,
I have been mostly lurking on this forum, I think this may be my first post.
I have a 70 chevelle with an LQ4, 80lbs injectors and an ebay turbo. I have been able to tune it to the point that it is 100% drivable and working great at WOT.
The problem that I have been chasing for a little while is that while sitting and idling. The Wideband tends to slowly read leaner and leaner, usually to a max of around 16:1. When the car is up to operating temp, but recently started (within 10mins) the wideband will read closer to 13:1 at idle. I have compared the reading on the gauge and what HPT is seeing, they are within .1 of each other.
The weird part is, everything seems to say constant.. except the AF reading.
Everything mentioned above was while the car was operating in full Openloop (STFT and LTFT turned off.)
Today, I decided I would turn STFT back on and see where the car wanted to idle. I noticed that using the narrowbands the car seems to want to idle in the 15.7-16.2 area (on the AEM wideband.) Even though the narrowbands are programmed to target 14.7. Please see the attached logs.
My question is: Which is more accurate? The narrowbands or the wideband. The narrowbands tend to read pretty close to each other, and the VE table can't be far off of what the narrowbands are reading since fuel correction is less than 5%. Does anyone see anything weird about my log? I let it idle until the car was good and warmed up.
Please take a look and leave any insight or criticism you may have! I appreciate it all.
idletuning.hplChevelle tuning.cfg