Other day driving to work it started to stumble like air was I the system only 3 miles from work I work at ford dealership so I pushed see how close I could make it stalled mile from work had my buddy drag my truck hooked my truck up see what icp ipr ficm. Ficm voltage 48.5 key on and cranking was 48 v icp only read 200 psi at one point 380 but not enough to start I tried to unplug the icp and it jump to 1400 psi almost started but still wont fully turn over. Checked ipr valve and screen everything seems fin no dirt or metal shavings or torn screen. It does have smooth cranck no skip im leaning towards high pressure pump but not 100% sure since its a 2003 were having hard time air checking it without tearing top the engine down tried thew icp and threw back hpp but could not get air hose fit in the back any suggestions 2003 6.0 with 62000 miles always change oil and fuel filters every 7000 miles I run full synthetic oil and fuel treatment

 

Ended up being high pressure pump fired right up no miss no codes