bus air over pressure...

[trystero]

If you were to accidentally over-pressure (maybe 150-170 lbs...) the bus air system via the schrader valve at the back of the engine compartment could you damage something that would keep the engine from starting?

I've been starting the bus regularly (to listen to the new sound of my exhaust...) and it ordinarily starts like a switch.

I went to start it this morning and now it turns over but doesn't start. Or even sound like it is trying to start...

Front and rear ignition same thing.

The only thing I can think that I have done since last starting is the air thing. BTW, It filled and everything seemed fine. Stayed aired up the usual amount of time... I think that the step is fixed once and for all...
It wasn't until not starting that I even considered that I might have damaged something using external compressor that I forgot to check the output pressure on before using.

I need a direction to head here to fix this. Any ideas? Thanks in advance!

Robert

[Randy Dupree]

you need to check the fuel shut off on the engine,see if it moves when you turn the key on and off.
Do you know where that is?

[DW SD]

I'm guessing your kill switch mechanism, which is air operated.
Maybe your control solenoid is stuck?
Is the engine kill piston engaged while cranking?

This happened to mine recently.

Doug

[DW SD]

I had the same symptoms, good cranking, no fire.

When I fixed mine I removed the flex lines, cleaned and used a bit of marvel mystery oil injected into the 12V control solenoid. From there, I cycled it a bunch of times. It has been flawless, since. On another thread, I posted a picture of the 12V solenoid.

Bear in mind, when you apply 12V, it closes the valve. So with no 12V, the valve is constantly open and the engine kill piston engaged.

Doug

[sfedeli]

If you over-pressurize, a blow-off valve will open on the air dryer. My house compressor is set for 150 PSI, and I air up the coach regularly with the shop air. Never had a problem with stuff not working. I'd suspect that the Schrader fuel shutoff solenoid just needs a little lubrication to make sure that the pin fully retracts when you try starting the coach. There is also a red Allenaire solenoid on my '85 that requires a good ground to open up and allow air to escape the Schrader shutdown valve, otherwise, the pin will stay extended and prevent the throttle from opening.

[trystero]

(man I love this site...)

Thanks for the input! I'll get on this tomorrow with the leads you guys have given me. Hopefully, a little education and fix and not much more... i feel absolutely helpless when my escape pod won't start

[DW SD]

Robert,
There's some pictures here of the control solenoid - it is mounted about 18" to the left of center just above the rear bumper: http://www.wanderlodgeownersgroup.co...olenoid+engine

In my case, I removed the lines, cleaned, lubed it and now it works great. The shraeder solenoid is a slave cylinder to the controller.

Doug

[trystero]

Randy, I don't know for sure where that fuel shut off is located. My bus is powered by an 8V92. Is the shut off above the primary fuel filter? There is a device there with what appears to be an air line to it. I'll get heavily into this tomorrow even though staying up all night stressing like a rat on acid sounds appropriate for me.

[trystero]

And Doug, Thanks! I'll get into this... It is not clear to me what function an air solenoid performs in letting engine run... or not. Why does engine care whether there is air pressure?

[trystero]

Alright... There is an air-operated solenoid that shuts off the engine. That makes since. I do remember some weeks ago trying to shut down the engine before air pressure was built up at all and it wouldn't kill until I had maybe 60lbs...