RCCUMMINS89 wrote:I didn't mean it can be turned in more than hang. I am surprised that it is hanging.......you sure the throttle isn't sticking by chance?
By all means, if it is hanging...... it is hanging, and runaway is near.
However.......I'm sure some will say differently. I have never seen a truck that (properly indexed, and the 3800 and 4200 springs are longer in stock form) one couldn't completely remove the idle screw......and then turn in the power screw til idle was right. AND NOT RUNAWAY.
I have also personally tweaked dozens of trucks that folks said were hanging........that I tested and were not hanging, cranked in the screw with the above method and the truck didn't runaway.
NOW...... please do not go out and do my above method and hope for the best. if it is hanging, it is hanging. But are you sure it is actually hanging, or is it coming down ever so slightly slower than before? Or maybe the throttle is sticking?
Perhaps what I was experiencing was an overly concerned reaction to my perception of a slow returning idle.
Per your suggestion, I re-indexed the throttle shaft back to how it was when I bought the truck, one spline back from where I had been running it the last couple of weeks.
Then experimented with the main fuel screw. It had 5/8 of a turn left in it. The screw went from a little resistance to turning it, to feeling as if it were bottoming out against something. I locked it down there since I don't know enough about the inside of the pump to force it any further.
When I previously had the shaft indexed one spline, I backed the idle screw all the way out and it still idled high at 1100 rpm, today with the fuel screw now bottomed out and the throttle shaft back to "original", I had to turn the idle screw out to maintain idle or it would die. The fuel screw would not maintain an idle by itself without some input from the idle screw.
So, it has some more torque now and is back up to 23 psi at WOT in 4th gear. The boost raises quicker in 5th also, going up to just under 20 psi, whereas yesterday it would only achieve 16 psi in 5th at the same speeds. It definitely produces more smoke when rolling into the throttle, not really any smoke under higher rpm and WOT after the boost has risen.
I do have some wetting around the injectors. Note sure yet if it is the injection lines or the return lines. I did snug everything, but until I know what to tighten further, I don't just want to keep tightening. I will have to dry everything up and try to find the culprit(s). I mention this to ask the question: Can wetting / non-spraying leaks at the injectors cause great power losses?