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Here is my FORScan PERDEL graph. It was taken after going for a drive. Engine is fully warmed up and trans is in P. Issues have been a rough idle when warmed up--not too bad, but I can feel it--and lack of power when towing. It's hard to see in the screenshot, but the % ranges are:
1: 0-0
2: 0-1.25
3: 0.81-3.44
4: 0-1.06
5: 0.81-3.44
6: 0-0
7: 0-0.81
8: 1.63-4.81
From the link, it looks like your numbers are normal, even for #8, but getting up there. How many miles on these injectors?
Lack of power when towing has a few areas to check, starting with fuel pressure, oil pressure (IPR/ICP) and airflow (EBP, boost). Towing heavy revealed issues on my truck too. Any other data you can provide might help us.
The truck has 320,000 miles, and I don't know if/when the injectors have ever been replaced.
With the engine warmed up and idling, I get 11% IPR, 460-500 psi ICP, and 16 psi EBP. These go up to 39, 2879, and 44.8 respectively during WOT from 0-50. Here's a graph of going up a gentle hill, unloaded, in overdrive, then dropping to idle.
I've also noticed that when towing, occasionally I get a high pitched noise, like a squealing belt pulley, when over 2500 rpm. This never occurs when empty even at high rpm.
3, 5, and 8 usually show worst for mine too, see below. But as Jeff noted, still within normal. Well your 5 has a bit more variability, mine rarely goes over 1%. Looks like the ICP sensor is working (at least at that moment) but it's still worth pulling the wire off the top and checking the sensor for oil. And check that the tin nut on the IPR is snug.
There is some oily grit inside the ICP sensor. Not just oil, but solid stuff. When I unplugged it the pressure held rock steady at 725. Otherwise it fluctuates between 460-500 at idle. Unplugging it seemed to smooth out the idle also; less fluctuation in rpm.
Unplugging the ICP sensor will force the PCM to send a default value to the IPR. If that makes the idle smooth, while a "real" reading makes it rough... well then the "real" reading sucks. That, plus you found the ICP oily, pretty much confirms your ICP is bad. OE is the best choice for sensors.
