Attention: TDR Forum Junkies 
I posted this in Truck 911, but as I currently have it running, it probably doesn't belong there anymore.
I am looking for some information on what could be keeping my truck from running in fairly mild cold temperatures.
Long History
-2003 truck, HO, auto, stock except for air intake and filter
-About 196k miles
-I have had it about 110k of those miles. No major repairs (except wear parts in the drive line and suspension)
-I rarely plug it in, as it rarely get super cold (below zero)
-Recently it did drop to about 14 below for a couple of nights. Forgot the first night, and it wouldn't start. Remember the second night, and no problems.
Recent History
-Wed to Thursday, truck was at the airport in the teens (zero at night). Started no problem.
-Filled the tank, drove home. It was about twenty over night, so I didn't plug it in.
-No problem with the drive home, and it was a major station, so I doubt the fuel was old or bad.
-Friday, truck would not start. Again, about 20 degrees. Plugged it in, and a few hours later it started.
-I left it plugged in, but apparently the GFI tripped at some point. It won't start again.
-For all of these no starts, it cranks fine. Not a voltage problem.
Analysis
-I have verified plenty of voltage, grid heater is working, and block heater is working (unless GFI trips)
Work Around
-Seems to start fine when plugged in. I will keep it plugged in, but I don't like spending $3 to $4 a day on electric to run a heater in barely below freezing weather.
-Also, I am worried it will leave me stranded someplace.
Question
-Why all of the sudden has my truck developed a dislike of barely cold weather. It used to start fine down to zero, and only needed to be plugged in when it was sub zero. Why, with 20 degree nights and 30 degree days, has it become a problem?
-Why, when it dropped to zero during the time it was at the airport, did it start then and not now?
I am looking for some information on what could be keeping my truck from running in fairly mild cold temperatures.
Long History
-2003 truck, HO, auto, stock except for air intake and filter
-About 196k miles
-I have had it about 110k of those miles. No major repairs (except wear parts in the drive line and suspension)
-I rarely plug it in, as it rarely get super cold (below zero)
-Recently it did drop to about 14 below for a couple of nights. Forgot the first night, and it wouldn't start. Remember the second night, and no problems.
Recent History
-Wed to Thursday, truck was at the airport in the teens (zero at night). Started no problem.
-Filled the tank, drove home. It was about twenty over night, so I didn't plug it in.
-No problem with the drive home, and it was a major station, so I doubt the fuel was old or bad.
-Friday, truck would not start. Again, about 20 degrees. Plugged it in, and a few hours later it started.
-I left it plugged in, but apparently the GFI tripped at some point. It won't start again.
-For all of these no starts, it cranks fine. Not a voltage problem.
Analysis
-I have verified plenty of voltage, grid heater is working, and block heater is working (unless GFI trips)
Work Around
-Seems to start fine when plugged in. I will keep it plugged in, but I don't like spending $3 to $4 a day on electric to run a heater in barely below freezing weather.
-Also, I am worried it will leave me stranded someplace.
Question
-Why all of the sudden has my truck developed a dislike of barely cold weather. It used to start fine down to zero, and only needed to be plugged in when it was sub zero. Why, with 20 degree nights and 30 degree days, has it become a problem?
-Why, when it dropped to zero during the time it was at the airport, did it start then and not now?
