| Author | Message | ||
| Andrew Bowey (All2go)
Registered Member Username: All2go Post Number: 10 Registered: 12-2006 Posted From: 71.31.225.5 Rating: N/A |
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. | ||
| WILLIAM D. WATKINS (Sivrtnge2)
Registered Member Username: Sivrtnge2 Post Number: 73 Registered: 11-2006 Posted From: 76.97.110.75 Rating: |
Sounds like you have a fuel filter loose and it allowing your fuel system to lose its prime!!! | ||
| John Harrelson (Jharl)
Registered Member Username: Jharl Post Number: 53 Registered: 7-2005 Posted From: 65.175.209.60 Rating: N/A |
make sure the mouse trap is set and the piston is pushed in in the thing across from where the accerator is. I could not start mine this spring to save my life. the return spring had failed and the piston thingy would stay out. i replaced the return spring and pushed in the rod thingy and the bus syarted as usual. jack | ||
| John Harrelson (Jharl)
Registered Member Username: Jharl Post Number: 54 Registered: 7-2005 Posted From: 65.175.209.60 Rating: |
above post is for only the very technical and whom can spell. | ||
| Andrew Bowey (All2go)
Registered Member Username: All2go Post Number: 11 Registered: 12-2006 Posted From: 71.31.225.5 Rating: N/A |
Hey that may be it . The piston thingy is still stuck out and I will go and try pushing it in and then starting the bus. I can spell and that is just technical enough so I can understand. Great advice. Thanks. I'll let you know if it works. I will double check the fuel filter but it would not start before I changed the filter...that is why I changed the filter, and it was running fine previously so it does not seem to indicate I am losing prime. It is tight, I just did it this morning and topped them up really full. Thanks though. Andrew. | ||
| Andrew Bowey (All2go)
Registered Member Username: All2go Post Number: 12 Registered: 12-2006 Posted From: 71.31.225.5 Rating: N/A |
Ok, I tried the upper piston and the rod would not push in? It is out all the way. There are two, one closer to you as you stand at the back of the bus and one a little further in on the throttle control mounting plate. It is the one further in that will not go back in. This is the engine shutdown cylinder and that is more than likely my problem. Is the piston rod supposed to be out or in to start? Andrew. | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 203 Registered: 8-2006 Posted From: 207.231.80.150 Rating: N/A |
Afternoon, Andrew, The way the thingy works, (shutdown cylinder to be technical) is to have air pressure applied to it by the "Skinner valve" as most of us refer to it. This is an electrically operated air valve, with one hose coming from the bus air supply, and the other going to the thingy, with two wires attached. In fancy electrical engineering terms, the Skinner valve is "normally open." What this means is that with no electricity to it, it will allow air to flow, which will push the piston out of the shutdown thingy. With electricity, it closes the supply from the bus air, and vents the trapped air in the shutdown cylinder, so the piston retracts with a spring. All of these mechanical buses work this way, and need air to shut down the bus! What I am saying, is that if you start your bus after sitting long enough that the air has leaked off, and turn off the master switch before air has built up, the engine will not stop. BUT, sitting with the switch off, and air in the bus, the piston should be out. Quick and easy check. Disconnect the hose from the end of the cylinder. If no air pressure, and piston is out, the cylinder is the problem. Be aware that an aired up bus will give you reservoir pressure there, with the switch off, (and with it on if the valve is bad!) If disconnecting the hose shows air pressure, and the piston retracts, leave the hose off, and try to start, REMEMBERING THE ENGINE WON'T STOP WITH THE SWITCH! (Just push the lever the piston pushes to stop.) If the engine starts and idles ok, and air is blowing out of the hose, either the Skinner valve has failed, or you have an electrical failure. I am an MCI owner, and my bus has an automatic shutdown feature wired into the Skinner valve which will stop the engine for either high temperature, or low oil pressure. Now, as the engine has no oil pressure when starting, how does it start when the bus has air? Well, there is an override on the Skinner circuit as long as the starter button is pushed. I don't know what or if yours has, but here's a whole bunch of things to look for. The "mousetrap" referred to above is a butterfly valve in the air intake. It is spring loaded, and will snap shut when the latch is triggered, by the electric solenoid on its side. It also has a little manual trip button about the size of your thumb. It is used to stop a runaway engine, which is either caused by a stuck injector, or running in combustible fumes. Push the arm up under the latch until it clicks. It is triggered by the emergency stop switch at the driver's controls, and inadvertent pushes (blame the kids) have caused many of us grief. The engine will turn over and not start, and throw out big white clouds of fuel vapor. If you have no visible smoke of any color while trying to start, you have no fuel being injected, either because of lack of prime, as mentioned above, or because of a stuck shutdown cylinder or failed Skinner valve or wiring holding the shutdown piston out. HTH, tell us what you find, please. George | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 204 Registered: 8-2006 Posted From: 207.231.80.150 Rating: N/A |
Andrew, You got in between us, I got wordy again! I will ASSUME that your gov is the same as mine, I'm pretty sure it is and you have fast idle, the shutdown plunger pushes on the shorter lever, and only has the one hose out of it going up to the bulkhead. The fast idle circuit has TWO cylinders, fed off of the same hose, with a tee behind one of them. The fast idle cylinder on top of the governor near the shutdown cylinder prevents the throttle from being opened while the engine is in high idle. The other cylinder in the high idle air circuit is on the side of the governor, and pushes directly on the end of the fuel rack. You can't see that, but you can see the top cylinder's piston interfere with the throttle linkage, if its out. I'll shut up now. George | ||
| Andrew Bowey (All2go)
Registered Member Username: All2go Post Number: 13 Registered: 12-2006 Posted From: 71.31.225.5 Rating: N/A |
Thank you. That was great! With the excellent description of how it works 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. Fantastic! If you guys, George that means you, could explain some other things I might even get to finish this poject. It was supposed to take a year and I am into three now! I am going to start another thread on "how do I get power from the generator to the inverter?" If I get the same qaulity advice I can go far!(in my bus that is). Thanks so much, Andrew. | ||
| Andrew Bowey (All2go)
Registered Member Username: All2go Post Number: 14 Registered: 12-2006 Posted From: 71.31.225.5 Rating: N/A |
That post proves I really can't spell or error check! Quality! Andrew. | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 206 Registered: 8-2006 Posted From: 207.231.80.150 Rating: N/A |
Andrew, Posts like yours make it all worthwhile. We don't care about the spelling, and more importantly, neither does the bus! Thanks again, George |
