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Vibration on acceleration/ no boost untill 2000 RPM

2K views 4 replies 2 participants last post by  Upsidedown7.3 
#1 ·
Hello I am new so I will try to include as much info as I can.
The truck is a 02 f250 7.3l xlt long bed, 6 speed 4x4. The problem is a vibration that occurs in first gear. It maybe happening in second gear but not noticeable. It is worse going uphill. The truck has a 4 inch lift ( blocks in the back springs in the front) it has done this since I bought the truck and before the lift.
The yolk on the differential was worn an has been replaced. The u joints, trans mount, pilot bearing,
Flywheel, clutch and carrier bearing
Have all been replaced. The carrier bearing was shimed properly for the lift. The motor mounts have no visible cracks but, has a visible movement at startup. The injectors have been replaced with swamps stock. The turbo has a pre 99 wheel.
Cold side has been checked for leaks under pressure. No leaks.
I have boost, fuel and EGT gauges
They look normal, except boost doesn't start untill 1800 RPM.
I have one soft code for ebpv. The pedestal has been deleted and have a fooler for the sensor. I am using forscan on a laptop. KOEO Map is at 13.8 and ebp 13.9 baro is giving me a value of 1. $ or 0.0 This seems to be a problem right? CCT
fails cylinder #3 Buzz test was done on a cold motor and sounds good. I am not with the truck right now. Looking for ideas. Thanks
 
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#2 ·
First off, make sure the blocks are not tapered, if they are not. Try shimming the carrier bearing another 1/4-3/8". The short driveline can cause this and the shims from the lift are really for the crew cab long beds. I have mine shimmed an extra 3/8.
 
#3 ·
Ok, the blocks came from super lift. I will check for a taper. By what you are saying the top of the block or the bottom of the block would not be level, correct? The truck had these symptoms before the lift.
The lift didn't change it one way or the other. But I will check for a tapered block just to make sure.
 
#4 ·
For any one having the same issue, I was using the wrong PID in Forscan for the map sensor. The right PID now shows 14.1. I used the CCT and it showed cylinder# 3 failed. I looked at PERDEL % and all cylinders showed 0.0 with little fluctuation except cylinder 3 , which has 2.25% pretty steady. So I am in the process of figuring out what this means.
Baro sensors still show 0.0 or 1. $ not sure why that is. I have seen on other post baro with forscan at 0.0, but there is no explanation on why. Data on the net
Shows the truck should have a constant reading of the barometric pressure with KOEO. Other folks have posted baro readings with forscan. Maybe a 2002 pcm thing.
 
#5 ·
I now think I am dealing with two issues.
After doing more research, It is possible there is not enough shims at the carrier bearing. I used my phone and made a video of the diff shifting up. So it appears to have axel wrap. I planning on shiming the carrier down more to see if it helps. On problem two. When I hold the pedal at 1000 rmps the truck shakes. I came across the Nick mod and changed the cps to the CSS1103. The perdel on cylinder number 3 dropped to 0. When
the engine is cold all the perdels are at
0.0 or very close. After the engine is at running temp. Cylinder 1 goes to 1.50%
There rest are under 1%. With the new cps, if I hold 1000 rpms ( at operating temp) the vibration is worse and it blows white smoke until 1200 rmps. So I now
suspect a injector/o ring, wiring issue, PCM/IDM.
 
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