We have a 2003 F250 6.0L 180,000 miles . Recently on a trip we had to replace the fuel pump. After that it all seemed to go downhill. Truck accelerates fine until 3000 rpm and then the pedal goes all the way to the floor and dies. It just does not want to accelerate! Took it to Ford, told us nothing was wrong with it. Replaced all the fuel filters, brand new IPR put on truck recently, FICM tested good. Took off and cleaned EGR Valve and truck still dies intermittently. Every diesel tech who has looked at it has no idea what is going on. The truck idles rough between 1,500 and 2000 rpm and then dies and blows white smoke when you accelerate to 3000 rpm. Was thinking about replacing CAM shaft sensor..but at a serious loss as to what could be wrong. We have had it at Ford 4 times now and they have no idea what is wrong with it, and they are costing my wallet a fortune just to look at it. Any suggestions as to what to try next?

 

Why was the fuel pump replaced? What is fuel pressure at now? That should really be tested. RPM is controlled by fuel, so if you can't get any RPM's you're not getting fuel. Either by low fuel pressure, or another issue. What fuel filters were used? I'm assuming OEM Ford right? Why was the IPR replaced? Who tested the FICM? The batteries should be load tested first, then test the FICM and it should be tested COLD. Are you saying the truck is idling between 1500 and 2000 RPM? Or is it breaking up at those RPM's as you accelerate? Where are you located? We can probably get you in touch with someone who knows how to actually diagnose one of these things...