Motor problem- Totally bummed.

[gus]

I know there was mention books before but I have made it a habit of sitting down and absorbing the manuals. In the 18 mo I have owned the bus I probably read my 4104 manuals three or four times because it was all so new to me. I probably read them two times before I even went after the bus.

This has saved my bacon more than once. The first time was when I had accidentally hit the engine shut off switch in the engine compartment. The engine would start and run fine until the air pressure built up enough to shut it off-bummer. I spent an hour or two scratching my head and finally remembered reading about that switch a few months before. Switch off-problem solved!

There is no way you can learn to maintain a bus by book only but it sure helps to figure out what might be wrong and the parts book drawings are really great when you're removing something or taking it apart.

[Nusa]

Reading this I keep wondering why the flapper shutdown failed to kill the engine by starving it for air? You experts don't seem to be concerned about that aspect, but I have to wonder. Does it mean the flapper shutdown is leaky or defective in some manner? Obviously the engine was still getting enough air to run.

[Sojourner]

Flapper  valve is Not mean to kill the engine but only to keep from running high damaging RPM.....limited oxygen (restricted air flow) cause low power & RPM at any throttle position.....while the more throttle = more unburned fuel = wet fuel vapor or some black exhaust smoke at a given amount of restricted air intake.

If all intake air leaks is sealed off 100% than is will kill engine but flapper is NOT design to kill engine...only to limited RPM period!

So to truly shut down diesel at any given time is to shut off fuel injector's injecting fuel so it will quit running. Another word...if fuel injector is "stuck open" to cause engine RPM to run wild then flapper valve is use to save unnecessary engine damage....if it still running (low safe RPM) then pinch flex hose from fuel pump outlet with large 6" "C" clamp only enough to stop fuel flow.

However in Chaz case....Before ever starting diesel engine & driving....need to learn to where to shut off engine manually in case of some unexpected reason to not able shut engine down in normal matter.

Shop manual is for owner who want to have full or some control of what to do in case something went wrong. And re-read few time to be very knowledgeable where, what, how, when about everything in engine compartment as well bus chassis.

Remember most young modern diesel mechanic have no idea where manual shut off is on 2-cycle diesel. So help is very limited on the road to your journey.

Sojourn for Christ, Jerry

[DrivingMissLazy]

I had the rack on my 6-71 stick open on my 4104 as I crested a mountain top in California. I did pull over in a truck turn out before I actually figured out what was happening. I then turned on the air damper and it did stop the engine, but it was only running on five cylinders due to a stuck injector. I do not know if that made a difference or not. I did not damage the turbo seals by this action.
Richard

[gus]

DML,

For the benefit of the rest of us 4104 owners, did the rack or governor stick?

Tell me more about the turbo, I've been thinking about installing one.

[DrivingMissLazy]

An injector stuck, holding the rack open to full throttle position. Quite scary really to top one of the California mountains and let up on the throttle and nothing happens. Once stopped and the engine shut off, I removed the valve cover and loosened the bolts holding the stuck injector. Have no idea now how I determined which one it was. That was probably 25 years ago. Screwed up the valve cover gasket and everything was covered in oil by the time I got home. A couple of hundred miles probably. She also smoked like a banshee the rest of the way home.

I really found out from RJ that I never had a turbo. Just the standard blower. All of this was way before the advent of the internet and the board and i was working without much prior experience or help. I spent quite a bit of time down at MAK's shop picking his brain and his mechanics brains. Thanks again MAK.
Richard

[Chaz]

I take my bus in monday night to have the rack run. I hope to be doing some "brain picking" myself!! At least with some hands on knowledge, I may be able to understand what the book says a little easier. Otherwise, I just read over it and it doesn't sink in. 

  Chaz

[gus]

Richard,

Thanks for the info, another bit to put away in the old thinker for future reference!