TIMMEH

Okay so I'm logging my recent tune attempt, and I notice that I'm in fuel cell 22...in regular driving...not at WOT. This was after I'd just turned the car on and started driving. Later I did a WOT run and it recorded in fuel cell 22. Right after I fired the car up and waited for it to stop surging, it was in 20...once I started to go it went into 22 and stayed there. When I stopped at a stopsign, it went into 4. As soon as I started to go again, back into 22. Then it went into 9, and back into 4. Then 22, 21, and 22 again. Once it warmed up a bit it was cruising in the regular fuel cells like it's supposed to, and jumped into 22 at the WOT run.

Ideas?

Super Sport X2

20,21,22 are used any time the canister purge (evap system) is not running.
Canister purge has serveral qualifications to run. Engine restart time is one of them.

20 shows up during low TPS (2%), and low vehicle speed (3MPH). 21, 22 jump back and forth depending on where the current manifold pressure is for the lower LTFT MAP value.


GM used to use a lookup table to see what BLM cell canister purge was allowed in. It was never allowed in lower MAP, lower RPM ranges.

Now they do the opposite. It's allowed in all BLM cells, and jumps to it's own BLM cells when it's off. Depending on what calibration you have, the normal CCP BLM switch point is less than 4% CCP duty cycle.


Super Sport X2

TIMMEH

Hey thanks for the explanation! I'm trying rapidly to learn all this stuff. With ADHD it's a hard thing for me to do. I appreciate it.