I have a 2003 ford excursion 7.3, chasing an intermittent issue. While coasting at higher speed 35+ mph , then getting back on the accelerator, I get no response. On forscan lite, IVS shows off idle, and APP% is 30%, but ICPV voltage is .50 to .60 then it bucks and acceleration comes back. I swapped the ICP sensor and it made no difference. I used OEM ICP. The truck will also idle a little more rough once its warmed up (but its minimal). I attached a picture, I forget to turn my tuner off during the forscan so IPR% looks high, but with tunner off its at 40%. I have the issue whether hydra is on or off.

I'm in the process of checking wires. It seems like something is grounding out. At first look, no obvious chaffing. I found a WH/LG and WH/RD wire on driver side 42 pin connector with tiny nick, but the defect is not touching anything. When I removed the 42 pin connector, there was dilectric grease, don't know if thats factory or not. I also see these red plastic clips on three wire, the red clips look like some sort of tap (pic). So far, the rest of the wire bundle is in tact, but its a little brittle no obvious issues. The truck has 179K miles, original injectors and glow plugs.

Questions.
What are these red plastic clips are they factory?



Should I pull valve covers and check / swapping UVCWH?
With the valve cover off, should I also replace injector Orings? I understand orings probably have nothing to do with the issue, but since the covers are off, I have access.
I'm contemplating swapping the harness with a new one. I have a large family, this is our adventure vehicle, I plan to keep for a long time. Where can I get quality engine wire harness?

 

I'd go after the IPR valve before the ICP sensor based on what you're saying. What does IPR duty cycle do while the problem is happening? What happens to it when the problem resolves?

 

Do you have the moveable pedals..? My 02 Ex and my 02 F350, both had the adjustable pedals, the accelerator pedal assy. was bad, I ended up going the cheap Non-adjustable rplc'ment route as it was like $140 compared to the $800 for the adjustable set-up, bolts up, plugs up the same. My F350 was doing weird stuff like that prior to it really wigging out, took it apart and the contacts inside were worn out... by wigging out, I mean it had zero throttle at idle, then when you wiggled the pedal as you pushed down it would sporadically throttle up, had to get it towed home.

 

Those red plastic clips are T-taps and are toys of the devil. Smite them from your truck!

 

And whoever invented them, they should be smited even more! Hate those stupid a$$ things! Oh, so you would like to create electrical problems on down the road for yourself ehh..?! And for anyone else who may buy your truck years down the road, or work on it... ugh.. YES, smite them from your truck!

 

yup,
they cut right through half of the copper strands, and leave huge open air gaps allowing Air, Salt, and thus corrosion to form and Halving the Current Capacity of the wire....