I'm going to copy my issue from a post over on Dieselstop...
Shudder, low power..... - Diesel Forum - TheDieselStop.com
also been posted on PSN
Shudder, low on power, tons of new parts, still issues - PowerStrokeNation : Ford Powerstroke Diesel Forum
2002 F350 with 320,000 km.
Starts very easy, does not burn oil, no black or heavy blue smoke, decent fuel economy, no check engine light.
When cruising at steady speed and torque converter locks up the truck shudders. (at about 1500 rpm) If I let off accelerator pedal the shudder disappears. If I increase rpm and cause truck to downshift the shudder disappears. If I switch off the overdrive the shudder disappears. The shudder is more pronounced if I have a load in the back of truck.
I also notice decrease in power while towing or if heavy load (full fuel tank) in back of truck.
Today an extensive test drive and stationary scan was performed (Snap On scanner) and I was told that #1 and #8 injectors are bad. Mechanic said this will cause the shudder. The scan was performed while stationary.
I'm not so sure at this point.
Any advice out there?
I'm having this EXACT same issue. I've been having my buddies at my shop help me out and have been using the Snap On Solus reader for troubleshooting.
2001 F350 SRW, ext. cab 4x4 with 239,xxx miles
So far this is what has been changed in the last 2 months
8- Brand new Alliance Power AD injectors
new under valve cover harnesses with $.25 mod/gaskets
new International Cam Position Sensor
new OEM fuel filter
completely rebuilt 4R100 trans
brand new billet torque conveter
even after all this work, the truck is still acting up, and doing exactly the same thing as the OP.
around 1500rpm under load or cruise 30-45mph, the truck has a definite hiccup-studder to it. Something is definitely NOT right.
Truck is blowing a whitish/blue smoke at idle and when on the accelerator.
No engine codes
good oil pressure per the scanner
PERDEL values are 0 across the board as long as the truck is moving (#2,#8 values go up at idle)
all tests that you can do on the SNAP ON reader come back with a pass
no issues starting the truck even on cold days (30 deg this morning, no problems)
Its driving my buddies and I completely crazy, and all our troubleshooting is not helping.
Any help would be greatly appreciated
2001 F350 7.3 4x4, ext cab, long bed, 4" MBRP, RiffRaff 6637 kit, 4 gauge ISSPRO w/ Aerotech OBD gauge, DP F6, 6.0L Mishimoto I/C, completely rebuilt 7.3 .010 over, WW, RR FRx, RR FRx