bus won't start

[oldallegro]

You pros must get tired of answering the same old questions, but newbies just keep asking. 
I have a special order MCI-9, 1990 bus

I started the bus last Firday, the 5th; and let it run for 10 minutes or
so to bring the air up to 90# and have the heat come on.


It was to go to Billings (then NY) on the 10th.  I went out to
start it at 2 p.m., an hour before driving it to Billings.  The
temperature at the time was 41 degrees.  It would not start-
would turn over, but not continue running.  I had someone
spray starting fluid into the air cleaner opening- again it would
fire, but not start.  It would run 5,10,15 seconds on the fluid.
The temperature was dropping, so I checked with a local
diesel mechanic who said the fuel might have drained down.
We removed a fuel filter and filled it with fresh fuel (I had 1/2 filled
the tank a frew weeks ago, so knew it had "winter" fuel in it.
We again used the started fluid, but it would fire and not keep
running.  Now the temperature was zero.  I called a friend who is
a diesel mechanic.  He said the engine need to be heated.  I
put a charger on the battery for the night, and a space heater on
the engine from 4:30 a.m. to 8:30 a.m.  We tried again with the
same results.  The diesel mechanic said it needed more heat,
so I borrowed a 155,000 propane heater & it was blowing on the
engine for 5 hours, plus I purchased two new batteris.  We had
same results.

Any ideas if this is just the weather or some bus problem?

[jjrbus]

A diesel needs 2 things to run air and fuel. If it will start on starting fluid you must have a fuel problem. When you removed the fuel filter was it full of fuel? Which filter did you remove primary or secondary?

[gumpy]

First suggestion...  get a new mechanic.

Second suggestion..  check your switches on the remote. Make sure the run switch is in the run position. There's a possibility that the air is up, and the switch is in the wrong position and it just shuts down. By spraying ether into it, it will run until the ether is burned, and then shut down.

At 41 degrees, you should be able to get it started and it might lope along till it gets all cylinders firing.

Watch your shutdown cylinder and see if it retracts when you try to start. It needs to retract for the rack to provide fuel.

Third suggestion is to check your safety shutdown, which consists of high temp sensors, low oil sensor, and low water sensor. if this is triggering, it will keep the bus from starting.

craig

[NJT 5573]

Oldal, sounds to me like it lost it's prime. If you don't know how to prime it you can call me. Larry 253 350 0925. The shut down valve could be closed, you can check that by turning the key switch on and off. You should hear it click back and forth at the back of the bus. If it doesn't, hot wire the switch. You didn't say what engine you have, but you may also have an emergency shutdown that will stop the airflow at the engine intake. Sometimes people play with things. When it gets cold if a fuel filter wasn't real tight it can shrink enough to let some air in the system,but check power to the switch first.

[Sammy]

Do you have a DDEC (computer), or mechanically controlled engine?

[Beatenbo]

If your 8 hasn't been tampered with or rigged the rear start panel will allow you to start shut down off or on by turning your main front switch on. You can then see if your throttle stop is retracting. Make sure the center switch is pushed all way up after remote start to make your charging system work. Left is off/on/center start/ right compartment light. Not so common to loose prime but wires from alarmstat, water temp sender can short out causing shutdown These 3 wires run across top of engine and down back to junction block. Engine heater great low temp. Good engine should start with one little starting fluid shot below 40 degrees. 2nd I wouldn't ask that mechanic another thing..

[NJT 5573]

I think you have a ddec 2. If thats right, and it has not lost its prime, even with the ddec coded out it should start and run for about 30 seconds. If it does that then check all the fluids for full. if they are topped of and it still runs 30 seconds and shuts off, unplug all the sensors and see if it runs. Don,t forget to unhook the fuel sensor w/ a screw driver. it's 1 wire that goes to a sensor by the fuel filters. If it won't run at all the ddec may not be getting any power. check the wire that goes to your master switch shut off for loose, broken,corrosion etc. I think it just lost its prime though.

[Beatenbo]

 I would think the MC 8s 73-79 would be mechanical. My 78 was an 8V71 no DDEC

[Dallas]

Where did MC8 come from?

I think he said it was a 1990 MC9.

[buswarrior]

Hello oldallegro.

If it was running before, and now it won't run on its own after sitting awhile....

Fuel problem is first place to look hard.

Re-prime the motor. Just filling the filters won't do it, you have to get it full of fuel, not air, tank to fuel pump. The fuel pump will not re-prime on its own, it can't pull air.

This is an exercise that you will have to do when you change filters, so welcome to your first big ongoing maintenance challenge.

Some get an electric pump and do some creative plumbing to put it parallel to the fuel line, some get a garden sprayer full of diesel and add some fittings to tap the rig into the top of the fuel filter assembly. And other variations on the theme of getting the system full of fuel, and empty of air.

Of course, you'll be wanting to find out where the fuel system is allowing air in when shut down, as this is most inconvenient!

And, don't talk to that mechanic about your bus any more. No guessing what other less than helpful advice he might give.

happy coaching!
buswarrior

[Sammy]

Sit iin the operator seat, turn on your master switch, do not try to start the bus at this moment,let me know if the "stop" and "check" engine indicator lights on the dash come on for about 5 seconds and then go out. The "stop" is a red indicator light, the "Check" is a green indicator light.This will let me know if DDEC is powered up. There are fuse holders in the battery compartment - they look like tiny black plastic boxes - they snap open to get to the fuse. IF the stop and check engine indicator lights don't come on, check those fuses.
Sammy 

[Beatenbo]

MC 8 ??  hat was I thinking  I must have read tooooo many post. Disregard and good luck.By the way I have a 1989 102C3  and it is a mechanical 6V92, no computer.