BCM Community

Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: all2go on June 24, 2007, 11:56:46 AM

Title: 4905 will not start
Post by: all2go on June 24, 2007, 11:56:46 AM
Hi all, my 4905 has been starting and running fine but now I went out and it just turns over and will not start. There is 3/4 of a tank of diesal. I just charged the batteries to get a fast spin on the starter and I just changed the fuel filters and topped them up nicely in case they were clogged. It still will not start. It is the spicer manual 8v71 and has never had a problen in 3 years. I did pressure wash the engine last week. It had a slow starting problem then and I attributed it to the water. There were two wires connected to the top of the spicer and one was broken. It was covered in grease and road dirt so I do not know if I did it pressure washing or it had been broken for awhile. I re-connected it. It eventually started and ran fine and I drove it 100 miles or so. Now after sitting for 5 days it will not start. Can anyone please point out some things I could check or do to diagnose this problem. Are there engine "kill" devices? that could be tripped? Or anything to do with the fast idle switch maybe? I'm lost. TIA.
Andrew.
Title: Re: 4905 will not start
Post by: larryh on June 24, 2007, 12:21:45 PM
You need to rebleed air out of system as it sounds like your check valve let it drain fuel back to tank. Pull your primary filter off ans see if it is full of air or fuel I'd bet the level is way down in filter.

HTH

LarryH
Title: Re: 4905 will not start
Post by: all2go on June 24, 2007, 12:52:28 PM
I will check on the filter level to see if air is in the line. Thanks. Andrew.
Title: Re: 4905 will not start
Post by: Dallas on June 24, 2007, 01:04:27 PM
I have to agree with Larry on the air in the filters and the rack. Anytime you remove filters, you have a chance of introducing air into the system.
How much fuel was in the old filters when you removed them? were they all the way up to the top or down 1/4 or more?
Did you fill the new filters up all the way to the gaskets before installation? To help remove the air from the system, remove a plug from the intake side of the secondary filter and squirt fuel in until full after each starting attempt.

Another thing to try, Check to see if the emergency shutdown butterfly is closed or partially closed. It may have been accidentaly tripped at some time or other.
If the emergency shut down is open, remove the rubber tube between the air intake and squirt some WD40 (Not PB Blaster, or any other lubricant) into the intake while turning it over. You could also use a small amount of ether (Starting Fluid), but be careful and don't use much. Just a 1 second spray will be sufficient, and only while turning the engine over.

Try these remedies and get back to us even if it does start.

Dallas

GO BUSSING!
Title: Re: 4905 will not start
Post by: captain ron on June 24, 2007, 03:29:58 PM
Check the valve that kills the engine. I had trouble with that one on mine after washing it once. sprayed some wd40 on it and it worked fine. But a year later failed again and had to be replaced
Title: Re: 4905 will not start
Post by: all2go on June 24, 2007, 03:33:52 PM
Thanks everyone. I was able to go to the back of the bus and with the key turned on I used the engine control/normal/off/rear run switch and the normal/off/rear start switch to release the pressure on the shut down valve, push the piston in...which it didn't need as I put my thumb on it it retracted on it's own and the bus purred to life like it normally does. Your descriptions really help.
Andrew.
Title: Re: 4905 will not start
Post by: superpickle on June 24, 2007, 04:00:43 PM
Yippeeeeee  You guys SAVED another one  ;D


This forum Rocks, for sure..  ;)


Good one Guyz !!!!!

Paul...
Title: Re: 4905 will not start
Post by: captain ron on June 24, 2007, 05:14:36 PM
Was there a little surface rust on the shaft? You might want to think about replacing the skinner valve if you have trouble again.
Title: Re: 4905 will not start
Post by: Dreamscape on June 24, 2007, 05:23:52 PM
I know because I experienced something similar. I pressure washed the engine, drove the coach for about 4 miles, horrible black smoke and no power. The emergency shutdown flap had become dislodged and vibrated closed, therefore NO AIR. I learned it takes three important things for a diesel to run, air, fuel and combustion. With no air nothing would work right. I also read alot about the emergency shut down system later and added a solenoid, that was not there before.
So much to learn and so little time. That sometimes is how we learn how things work, when they fail.

Happy Trails,

Paul

Dreamscape