I'm new to this so here we go....

2002 F350 single wheel 4x4, 280k miles chipped with a 6

My problem first started when the bottom of my sending unit broke off in tank causing me to run out of fuel at 1/4 tank. I dropped tank and repaired. A week later I noticed fuel dampness on my tank and discovered I crossthreaded cap on sending unit. About this time I started getting a shutter at slight acceleration only and a harder hit at idle. I thought air in lines so I dropped tank and reassembled. No air in line at all now but I still have a shutter so I replaced fuel filter in case of obstruction. No help. Now since I have owned truck it has been a pain to crank in cold weather if it wasn't plugged in over night. It has been hard lately even in moderate weather since shutter started so I replaced both batteries today (hope it helps). I replaced the ICP today also because I noticed the other day when there was oil on and around harness to it and when I unplugged it today the truck changed idle and there was oil inside. After I changed it I took it out and it still had the shutter and sound of a miss. At about 8 miles in it just died going down the road. I coasted to the side and it cranked right back up and drove home. The shutter doesn't fill as bad but there. Also I live in the mountains and on my way home after cutoff I had chip in Stock position and had to put peddle to the floor to climb hill. I've never had to do that. I'm getting worried I work for a living and caint keep throwing money at it aimlessly. I'm thinking at this point IPR or CPS. But I'm no mechanic so I could be completely wrong. Please help.

 

When you repaired the foot on your fuel intake in the tank did you clean, or better yet remove the screens on your sending unit, as in the hutch and harpoon mod (search the forum for these terms if you have never heard of these procedures)?

If not, your screens may be clogged and causing a fuel restriction. How exactly did you determine there is absolutely no air being introduced into your fuel system??

If your screens are blocked, an easy way to tell is to blow some low pressure air back into the tank using the hose that is currently the inlet to your fuel pump (with the fuel cap off). This may free up your screen temporarily. If this does work, then I would plan and dropping the tank and doing the H&H soon.

 

I checked for air by removing the canister top and looking for air bubbles while it filled up. There were none and it filled very quickly with one running of the pump...acutaually over filled the canister.
Also I did clean the two sock filters located inside the sending unit. I also checked them again on the second tank drop.
However due to a shoestring budget I did not replace the foot but simply ran a fuel hose so I would pick up bottom of tank.
I did notice some shavings or trash in bottom of canister each time I drained it.

 

Is it possible that the shutter could be coming from torque converter? Mine did this and the fins had laid over on the torque converter and symptoms were taking off from stop it would shutter. JMO

 

I hope you got a Ford or IH ICP, the aftermarket ones seem to have lots of problems. If there is oil in the harness there blow it out with some contact cleaner. If the oil is coming from the new ICP it needs to be replaced.

Is the check engine light on? Many basic scanners will not read the codes on these.

If the CEL is on check the engine harness where it goes across the drive side valve cover to the 42 pin connector. It can rub on the VC and short the wires on the bottom. Pull apart the 42 pin so you can inspect the bottom of the harness.

If the CEL is not on I'd look more at fuel problems. Maybe the added fuel hose in the tank got kinked or blocked? How much fuel in it now?

 

No oil from new icp. Got full tank of fuel. No CEL on. I've put over hundred miles on since icp replacement and it want kick the shutter.it starts at low acceleration in 2nd gear. At low take off there's no shutter but you can hear what sounds like a miss. By the way idle has gotten a lot better it sound almost normal now.

 

So just to reiterate.......idle sounds better however after it hits second gear any slight acceleration causes a shutter. If I back off accelerator or push to more rpm or passing gear it goes away. Does this in 2nd gear and up. I do not believe it is in transmission due to the fact I can hear what appears to be a miss in the engine almost like an exhaust leak...but I know it isn't I traced exhaust all the way back the block.......What is this? Could it be my ipr or as simple as resetting the cpr.

 

Only shutters after second gear and only at slight acceleration. Push or let off it stops but baffle sound still there. In first you just hear what sounds like a exhaust leak (baffled sputter sound) which I'm certain I don't have.

 

This is going to sound funny but humor me. Try greasing the slip joint on the drive shaft and check the carrier bearing if you have an extend cab or crew cab truck. I am not sure if the regular cab trucks have them.

 

HKUSP so I greased slip joint and replaced carrier bearing. The parts store said the one that fits mine however pulls up as a f450 in their system. Anyways replaced it and ran it......shutter gone. Slight acceleration is nothing but horsepower now baby!!!!! However now I have a constant vibration in floorboard in seat and a sound as if something flaming under truck around 55-65. Did I do something wrong. I noticed when I greased slip joint it was hard to put back to gather I figured because of grease. Is it possible I put too much and it's through ingredients of my balance or something.

 

Anything is possible, but did you mark where the driveshaft position was in relation to the yolk before removing?

 

I've heard this happens with an out of balance drive shaft... Make sure it was installed exactly as you removed it? I wouldn't have thought that mattered either but it's happened to a friend.

 

Oh it absolutely does matter! When something is spinning, especially at higher speeds any slight deviated in the distribution of weight can have a huge impact as to how smoothly said assembly turns. These are usually balanced as an assembly and in you put the two parts back together in any way at all from how they were originally set up it can cause all types of vibrational and harmonic issues. Always best to make marks on both halves of the shaft before removing and make sure they are lined up the same way on re-installation.