Figure This One Out!!!

[dleopard19]

03 f650 international vt365 6.0 diesel, this truck cranks and idles fine, but when you drop it in gear you have no throttle response and it has a very eratic idle, i have replaced the hpop, ipr valve, icp sensor and pigtail, epb sensor, egr valve, fuel filters, oil, and all the computers have been udated, anyways after the truck warms up it has somewhat of a decent throttle response but still doesnt run flawlessly, any ideas will help, please chime in if you have any ideas.

[HAM_RADIO_MAN]

What is your FICM voltage?

[Chango]

ficm voltage test in my sig under "troubleshooting a no start"

[ajpu1983]

Check for compression building up in your fuel system. I've had 4300s with just one bad injector act just like this. They can internally fail and allow compression in the fuel rail through the injector itself or the copper washer can fail.