when I hit a hill I am loosing all my power, even with the pedal floored it goes down to 50mph. I have replaced the pre filter, fuel filter, rubber fuel line section, new air filter and fresh oil and filter. I've replaced the valve cover gaskets and transmission. I am trying to get reliable power from my truck in a few months we are moving cross country and i am going to have to pull a trailer from the west coast to the east cost. any ideas on what could be going wrong?

---AutoMerged DoublePost---

oh yea, there is no black smoke ! it never really smoked a lot but there is only a little when i first start it and thats it. a lot less than normal.

 

do you have a boost gauge?

 

Check the "boots" in to and out of your intercooler. They seem to be notorious for slipping off, or sometimes getting torn.

Also, make sure that with all that upper-back-area work that the boost line to the AFC housing didn't get dislodged. If the pump thinks"no boost", it decides "no fuel", and you get wimpy power.

 

I had the same problem, it turned out to be the wastegate actuator was bad and leaking air (had to remove it and blow air thru it to verify). I bought a new one online for $40 but had to cut an inch off the rod and an inch off the eyelet to make it fit. now my truck has great pickup again and no more problems with hills, i can accelerate up them. just to be thorough i took the boost line off the back of the AFC housing and put new thread tape on the fittings. they were a tad discolored and looked like possible leaks.
If that turns out to be your problem i recommend buying one from BDdiesel. I went cheap cause i had to but cost me alot of extra time and headaches.

 

no boot gauge yet, do you know an inexpensive one to buy? i'll look into the wastegate actuator and see if that's the problem.

 

My cummins acts the same way. Have U had any luck so far???

 

not to sure if they came with one, but do you have a cat in it still? i know with gas powerd cars this is one thing that happends when they get clogged

 

yep, still haas a cat on it! NV makes you smog your diesels, but thats a good idea ill check it out.

 

thanks for the info and hope i helped =]

 

Sounds like a boost leak. Check all boots for holes or tears, then tighten all boot clamps. There are 4 boots, so 8 clamps. Then put a wrench on the intake horn bolts, they've loosend up on me too. If it's stock and there's no boost it won't fuel and slow you down big time.