BamZipPow -
Quote:
Originally Posted by BamZipPow
Well...found out something interesting today.
After a quick minute warm-up this morning...I made my standard runs in closed loop. After the truck sat fer about an hour, starting coolant temp was at 146°F. Started the truck up and waited fer it to go to closed loop. About 4 minutes later, it finally went to closed loop. Coolant temp had risen to 188°F. Ambient air temp was about 45°F. What gives? My normal coolant temp is about 206°F. 
I also noticed that when I coast, it registers as open loop when the injectors cut off. Hmmm... |
Arghhhh. Everything I am telling you is how my car works. It looks like your ECU/PCM behaves differently.
Let's look at it from a different POV. As a programmer, I might make the decision to *report* open-loop condition when I turn off the fuel injectors. Why? Because when I turn off the fuel injectors, the 02 sensor is not being used to control the fuel injectors. I am not *in* closed-loop operation.
In my 1999 Saturn SW2, this is what I observe :
1 - Coasting downhill in gear. Engine stays *above* 2500 RPM because of slope of hill.
2 - Scangauge continues to report Closed Loop
3 - Digital AFR shows Lean condition, proving DFCO
In this instance, maybe the programmer said, yes, I know I have turned off the injectors, but I also *know* that the ECU/PCM is still in control, so I will continue to report closed-loop.
Regarding 4 minutes to closed loop, I haven't seen that. I have a mild climate, so it is easier for my car. But 4 minutes? With a warm engine? I *want* to say failing 02 sensor, but I really have no idea.
CarloSW2