High idle at slow roll-normal at full stop
#22
Completely normal.
When rolling to a stop with the clutch in, the computer will keep the idle slightly higher than normal to keep strain off the clutch.
On start up, the idle will speed up a little higher then normal and the ignition will be in single fire mode. The ecm is looking for the crankshaft position sensor to sense a slight pause or slowdown in engine speed after one of the cylinders fires to determine the firing timing.
When rolling to a stop with the clutch in, the computer will keep the idle slightly higher than normal to keep strain off the clutch.
On start up, the idle will speed up a little higher then normal and the ignition will be in single fire mode. The ecm is looking for the crankshaft position sensor to sense a slight pause or slowdown in engine speed after one of the cylinders fires to determine the firing timing.
#23
Completely normal.
When rolling to a stop with the clutch in, the computer will keep the idle slightly higher than normal to keep strain off the clutch.
On start up, the idle will speed up a little higher then normal and the ignition will be in single fire mode. The ecm is looking for the crankshaft position sensor to sense a slight pause or slowdown in engine speed after one of the cylinders fires to determine the firing timing.
When rolling to a stop with the clutch in, the computer will keep the idle slightly higher than normal to keep strain off the clutch.
On start up, the idle will speed up a little higher then normal and the ignition will be in single fire mode. The ecm is looking for the crankshaft position sensor to sense a slight pause or slowdown in engine speed after one of the cylinders fires to determine the firing timing.
As far as the starting/single fire/CPS stuff...I don't know anything about that.
#25
#27
I probably should've explained it a little more.
You'll notice the higher idle with the clutch in when rolling to a stop. As you said, it helps to keep from lugging the motor at low revs but it does help keep strain off the clutch pack if you have to let the clutch out in an emergency or if you're doing something like coasting through a stop. At least, that's how it's been explained to me by wrenches with much more time in the guts of HD engines than I have.
You'll notice the higher idle with the clutch in when rolling to a stop. As you said, it helps to keep from lugging the motor at low revs but it does help keep strain off the clutch pack if you have to let the clutch out in an emergency or if you're doing something like coasting through a stop. At least, that's how it's been explained to me by wrenches with much more time in the guts of HD engines than I have.
Thread
Thread Starter
Forum
Replies
Last Post