No Start? Battery cranks starter, fuel gauge goes to 1/2 when key is on?

Vehicle is running now like it always has. I went all over the place trying to fix this one and it came down to only this: It seems to me that the dead battery caused the ECU to lose info on the throttle position sensor. I never push the gas pedal on a fuel injection vehicle, but just out of the blue decided to push it today for the hell of it and it ran and stayed running until I let off the pedal. I adjusted the throttle linkage so it would idle at 800 RPMs in park, and it continues to run. I drove it around for maybe 10 miles and I now have about 1,300 RPMs in park. Will adjust the throttle linkage back down to 800 rpm in park and I'm all set. Appreciate the help.