Attention: TDR Forum Junkies 
For all of you California Cummins owners, here is another reason why I left. That wonderful EGR system has caused another problem for my '97 BR3500 even though I took out the entire system three years ago.
Symptoms: All engine functions and gauge readings were normal but boost would only go to 12psi at 1800rpm and top off at 15psi when fully revved. Normally my truck runs in the 30psi range at 1800rpm but now it was running worse than a stocker, can't have that while hauling heavy equipment, eh?. Temperatures were normal, no excessive smoke, no sign of air leak, not a lift pump, not a clogged filter, not a clogged wastegate elbow and not a faulty overflow valve. In other words, this was something that I haven't come across in five years of TDR reading.
After exhausting my own efforts I took my beloved truck into the local fuel injection shop where I bought all the "enhancements". After a day of tinkering and analysing they still couldn't find the gremlin and I had to use my truck for work the next day, imagine that! I got home with my ailing truck, scratched my head a few times and took another look. Hmmm again. Give up?
I remembered checking the wastegate elbow, the aftermarket one that "fools" the wastegate into opening later, it was clean but I didn't check the control line. The control line is a 4" long flexible tube that goes from the manifold to the AFC, it is connected with brass fittings. I removed the plennum to get to it but still had to eighth-turn the wrench to get the fitting off because the fuel lines were in the way. Once the control line was removed and checked (it wasn't clogged but looked a little sooty) I removed the entire "T" fitting on the back of the AFC and checked it out. The control line feeds another brass fitting that has a very small orafice, about 1mm. AAAHHHAAAA! it was clogged with soot! All of a sudden it all made sense. The AFC wasn't getting ANY boost from the manifold so my torque plate was basically nullified. Further analysis would tell me that this soot undoubtedly came from my exhaust which could only have gotten there through that lovely EGR system, thank you very much! I wonder how much soot I have in my manifold and how often it will clog my control line fitting.
The good news is that it's a really easy fix, especially since the manifold end of the control line doesn't need to be removed. Just unscrew the AFC end of the control line, remove the orafice fitting and blow it out with air, done. After reassembling my truck is back up to 300hp and I'm happier than a pig in slop. Thanks for listening.
Symptoms: All engine functions and gauge readings were normal but boost would only go to 12psi at 1800rpm and top off at 15psi when fully revved. Normally my truck runs in the 30psi range at 1800rpm but now it was running worse than a stocker, can't have that while hauling heavy equipment, eh?. Temperatures were normal, no excessive smoke, no sign of air leak, not a lift pump, not a clogged filter, not a clogged wastegate elbow and not a faulty overflow valve. In other words, this was something that I haven't come across in five years of TDR reading.
After exhausting my own efforts I took my beloved truck into the local fuel injection shop where I bought all the "enhancements". After a day of tinkering and analysing they still couldn't find the gremlin and I had to use my truck for work the next day, imagine that! I got home with my ailing truck, scratched my head a few times and took another look. Hmmm again. Give up?
I remembered checking the wastegate elbow, the aftermarket one that "fools" the wastegate into opening later, it was clean but I didn't check the control line. The control line is a 4" long flexible tube that goes from the manifold to the AFC, it is connected with brass fittings. I removed the plennum to get to it but still had to eighth-turn the wrench to get the fitting off because the fuel lines were in the way. Once the control line was removed and checked (it wasn't clogged but looked a little sooty) I removed the entire "T" fitting on the back of the AFC and checked it out. The control line feeds another brass fitting that has a very small orafice, about 1mm. AAAHHHAAAA! it was clogged with soot! All of a sudden it all made sense. The AFC wasn't getting ANY boost from the manifold so my torque plate was basically nullified. Further analysis would tell me that this soot undoubtedly came from my exhaust which could only have gotten there through that lovely EGR system, thank you very much! I wonder how much soot I have in my manifold and how often it will clog my control line fitting.
The good news is that it's a really easy fix, especially since the manifold end of the control line doesn't need to be removed. Just unscrew the AFC end of the control line, remove the orafice fitting and blow it out with air, done. After reassembling my truck is back up to 300hp and I'm happier than a pig in slop. Thanks for listening.
