Ok 89 4.9L... never seems to get warm enough, anyway, i figured I would start with a thermostat and go from there. On the gauge, I'm getting to "N" of normal and stopping, maybe half way to "O" but never more. My question is this. At what point does the ECU, "get out" of "open loop mode" ? If I had a temperature it really wouldnt do me much good, as the word NORMAL doesnt translate into numbers well. If i'm inside the brackets --------> ( | [_Normal_] | ) is it out of that mode? Truck just seems like it needs a kick in the pants, and i'm just eliminating things one at a time. I did and have recently noticed a slight drop in RPM when hitting the gas, and dont remember it doing that before. Any help, and or ideas, thanks again... :)

Eric