2 Attachment(s)
95 LT-1 Idle Cell Comparison - Humidity?
Been struggling with this problem for roughly 2 months. After a bunch of experimentation I started looking for compression loss because it was struggling to start and stay running, and most of the time died when it switched to closed loop.
While I'm not leaning toward the ignition controller being the cause, as most of you know I'm running my experimental coil per cylinder controller (link in sig). It seems to run great once up to temperature, but it is certainly possible the ignition controller is a contributing factor.
At this point I can barely get the thing to start - it seems like it's not getting enough air. I've drilled the IAC bypass hole from 11/32 to 1/4 inch with little change. Cold starts barely stay running with the IAC pegged at 160 until the engine warms up. Once warm IAC counts are around 80 at 950 rpm.
So I'm looking for a simple explanation because the problem only appeared as the humidity started to climb right after the 43kpa frame was captured. Note the huge difference in metered airflow. I know the barometric pressure is higher in the 43kpa frame, but so is air temp. Aside from this the biggest difference between the conditions the data was captured in is that the 43kpa frame was from late spring with relatively low humidity (and 11/32 IAC bypass hole). On the other hand the 48kpa frame was captured a week ago in 65-70% relative humidity and 17/32 bypass hole. Can humidity and air density account for this much difference? All the MAF logs I have to compare to are 2+ years old and I couldn't possibly guess what the relative humidity was.
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Edit: I failed to mention that this is the first summer I've run this after adding the stroker crank (384ci - 4.040" x 3.750")