starting and running problems

[solodon]

Tried to start the MC9, only a click.  Started at batteries, lots of corrosion so cleaned things up and tested batteries.  Now all good.  Still just clicks.  24v at the starter.  Jumped solenoid connection and fired right up.   Tried to move bus but buried it in the soft ground.  Started digging it out etc. and the engine shut off as though I turned it off.  Upon restart had to crank longer (still jumping solenoid) than normal finally started.  Finally have a workable plan to move it, jump the solenoid, start the bus, move it onto pavement ( ), and the bus dies again.  All total shut itself off about 5 times today.  Still have to jumper the solenoid.  More diagnostics to do for the solenoid wire but why is it shutting down???

[lvmci]

Hi Don, look at the skinner valve post below, in the picture, the brass air valve in the middle pushes the arm to the right, still in the center, that arm is the fuel gate, that shuts off the engine by ending the flow of fuel. after starting the engine watch the brass air valve and see if it extends the silver arm pushing the fuel gate, if that is the problem, just disconnect the electrical wires to the skinner valve, the verticle stainless steel cylinder to the left and the engine will continue to run, but caution, you will have to manually close the fuel gate to stop the engine, practice this before attempting this with the engine running, I use a 18 inch screw driver to move the gate closed, be very carefully around that huge fan belt, lvmci...

[gumpy]

could be a number of things. Sounds like a safety shutdown problem (Low oil pressure, low water, engine temp) causing it to shut down.

Could be the stop/run switch on the rear control panel. Make sure it's in the run position.

Check your fuel supply. Make sure you don't have air in the system.

Check the skinner valves to make sure they are not defective.

Also, could be a defective master switch or stop/run switch.


You'll need to determine why it's shutting off. Is the skinner valve activating or is it just dying. You can determine this by watching the fuel shutdown solenoid
when it dies. If the fuel shutdown solenoid is engaged, then it's probably safety system or switch. If not, it's probably a fuel problem.

Once you know this, you'll have a better idea where to start looking for the problem.

[solodon]

Thanks for the responses.  lvmci, there was no picture that I could find with your post.  But I'll look at everything you guys mentioned later today.  I thought something safety also but temp, and oil are ok.  Low water light is on so I'll add coolant also.  Any special coolant needed for a 8v71?  From what I've seen anything is OK, nothing special.  Thanks again.

[robertglines1]

Prob got the green stuff in it.  This is a whole new subject because the wrong coolant can cause you problems.  Might just add a gallon of water for now then start a new topic. Might be time for a coolant change.  Detroit dealer has competitive prices most of the time or watch for fall sale..  Bob

[Scott Crosby]

If you need some more eyes or help just ask, I love to play with a bus.  I'm home in Avon for another couple weeks before I have to take a long road trip for work.

[lvmci]

Hi Don, here's a pic for you, hope this helps, were you able to keep the bus running? Lvmci...

[solodon]

found the skinner valves.  They're behind (forward of) the engine on the firewall like the pictures I found on a listing from Gumpydog.  Don't know if they are working or not yet.  Jumpered the starter again tonight, let air build up, didn't see anything out of the ordinary but not sure what is ordinary yet.  The fast idle isn't working either.  I shut the engine down and when I pressed the starter button heard a hiss from the engine bay with each press.  Couldn't hear the click I'd heard earlier and with no air there is no hiss....duhhh.  It's dark out now so after church tomorrow and hopefully with a helper I can do more.  BTW hooked a volt meter to the solenoid wire and when I activated the starter button from the engine bay there was no voltage.  Is there some sort of an interrupt in that circuit?  going to try looking at wiring diagrams in a little bit.  Again thanks for the suggestions and help.

[solodon]

    IT STARTS!!!!!!  PO stopped b y and said sometimes you have to wiggle the shift lever in neutral....wiggled...started.  Now to see about the shut down.  I'll let you know what I find out.  Again, thanks for the help.

[solodon]

Hi, well good news, sort of, I let the coach run for over an hour today.  It starts like it should and didn't stop running.  That's the good news.  The bad news is I have no idea why it shut down on it's own the other day.  I've put in over 14 gallons of coolant, and still do not see it in the sight glass on the tank.  Both valves are closed to the heater system as I've removed it, Man this takes a lot of fluid  .  Oh well continue with the work at hand, and take care of problems as they arise.  Everyone have a great day and tomorrow.

[lvmci]

Hi Don, good news, we generally use a smaller amount of anti freeze and mostly distiled water in the desert, for summertime, seems water cools better than antifreeze and it would be a good first rinse thru,to see what comes out before winter,  lvmci...

[Dave5Cs]

You said you added 14 gallons of coolant.Was that from empty. If so these old girls take about 24 total. But if you put in 14 now just add distilled water to fill finish filling. That also depends on if the antifreeze was a straight coolant or a 50/50 mix.

Dave5Cs from Galaxy S III

[RobSedona]

My mc5a has to have 24v to the skinner valve to just stay running

[solodon]

Hi Dave5c, thanks for the info.  I've removed all the OTR passenger system and closed the valves.  I always use a 50/50 mix and added 4 more gal. yesterday and when I moved it today, the low water light blinked so it's getting closer. 24 gal. for just the engine???   WOW  But then it is a lot of engine and makes a lot of heat so seems reasonable.

lvmci:   I like the idea of using mostly water but until I finally get on the road I'll be in central Indiana so a mix seems best for now.  Going to get some coolant additive to help top it off.  Seems to be no easy way to test the ph of the coolant, so don't know how much to add. 

robsedona:  Thanks, don't know how I'd check it yet but don't understand why it has been fine until Friday and fine since.  I'll keep it in mind and thanks.

.

[lvmci]

hi Don, don't forget the driver and front stair heater radiator, thats quite a distance there and back, in a 3/4" pipe, turn it off next to driver and from engine block, lvmci...