['03 POWERSTROKE]

Cannot keep engine running unless throttle is half to three quarters down. Tries to start and then dies. Glow plug light comes on while driving down highway and engine seems to die, but when light goes out it starts running fine again. Seems to run better when outside air temp. is cooler. Any ideas on what might be the problem. I just changed both fuel filters yesterday and did not help. Thanks for the help..............

 

[HAM_RADIO_MAN]

Any codes? What troubleshooting have you done? Have you checked FICM voltage? To get an accurate diagnosis over the Internet you will have to supply some solid data.