What could be the problem when stopped at signal, it doesn't want to accelerate. on 2004 Ford F-350 Super Duty

The truck doesn't stall out, it just won't accelerate. Been to a couple of shops including a dealership and can't seem to diagnose. It has been getting worse with time.

Asked by for the 2004 Ford F-350 Super Duty
do you have any eng codes? could be fuel issue or catt issue
Had it in a dealership and they could get any faulty codes. I've read it could be the ICP sensor, what do you think?
icp is on diesels like 6.0 and 6.4 i don't believe 6.8l have them. poss low fuel pressure?
This is a 6 ltr diesel. The problem is only when tring to accelerate from a stop.
sorry your post says 6.8l v10. this could be alot of issues with this piece, they are known for alot of problems but without knowning all the pid readings its hard to diag. normally the icp will not let trk run at all.could be ipr or high pressure pump with not enough pressure or a mulititude of other issues.we have been to school on these and the trk will need to be diag prior to any guessing. we have done alot of these several of my cust have 5 or more of these and they all wish they would have never bought them.i could look at it for you we charge 101.00 diag fee and est to for appt at 714-633-8219
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