No power climbing a hill from dead stop
Current Situation I have a 98 HR Imperial 40' motorhome with a Cummins mechanical 6CTA8.3 @ 325hp. My problem is no power on a hill from a dead stop. --I live in Tennessee in the hills, and do to ...
Forum Discussion
I think we might be getting to the problem.
The cold transmission doesn't help matters at all. I've stayed in a nice little campsite in Klickitat Canyon near Glenwood WA a few times. It's a fish camp, better suited for campers on trucks. I have about 4" clearance on each side (trees) to get in there. :B It's the kind of place where a 40' coach just doesn't look like it belongs. :)
The place is on the river, and there's a climb of about 6% either direction when heading out, and it's in the middle of a curve too. (The entrance is pretty much the bottom of a V notch) It's also a busy road for log trucks, and many's the cold morning when I'm patting the dashboard saying "COME ON, BABY, COME ON BABY, PLEASE, LET'S GO!!" as I'm looking in the mirror for the grill of a Peterbilt pulling 80,000 lbs. of logs that could be rounding the corner any second. When she's fully warm, she rockets away from the same kind of place. (Relatively speaking)
The manifold leak is a BIG issue, even if a small one. A turbocharger is a centrifugal compressor driven by a turbine. (compressor and turbine are directly coupled together) You'd be surprised at how a tiny leak can really effect the turbine's speed, and if there's no boost, it ain't makin' enough torque.
A stuck shut flapper (exhaust brake) will usually kill the engine, and it won't rev unloaded, so I doubt that's it. If it's all the way shut, it shouldn't even idle. But, an exhaust manifold leak will keep it from making boost until the RPM comes up. And, as mentioned, a cold transmission will keep the RPM from coming up enough in the first place, and when everything's warm on the road, the higher from-dead-stop RPM can compensate for the low boost and/or turbine speed.
The cold transmission doesn't help matters at all. I've stayed in a nice little campsite in Klickitat Canyon near Glenwood WA a few times. It's a fish camp, better suited for campers on trucks. I have about 4" clearance on each side (trees) to get in there. :B It's the kind of place where a 40' coach just doesn't look like it belongs. :)
The place is on the river, and there's a climb of about 6% either direction when heading out, and it's in the middle of a curve too. (The entrance is pretty much the bottom of a V notch) It's also a busy road for log trucks, and many's the cold morning when I'm patting the dashboard saying "COME ON, BABY, COME ON BABY, PLEASE, LET'S GO!!" as I'm looking in the mirror for the grill of a Peterbilt pulling 80,000 lbs. of logs that could be rounding the corner any second. When she's fully warm, she rockets away from the same kind of place. (Relatively speaking)
The manifold leak is a BIG issue, even if a small one. A turbocharger is a centrifugal compressor driven by a turbine. (compressor and turbine are directly coupled together) You'd be surprised at how a tiny leak can really effect the turbine's speed, and if there's no boost, it ain't makin' enough torque.
A stuck shut flapper (exhaust brake) will usually kill the engine, and it won't rev unloaded, so I doubt that's it. If it's all the way shut, it shouldn't even idle. But, an exhaust manifold leak will keep it from making boost until the RPM comes up. And, as mentioned, a cold transmission will keep the RPM from coming up enough in the first place, and when everything's warm on the road, the higher from-dead-stop RPM can compensate for the low boost and/or turbine speed.
