Bleeding Fuel Systems

[cowboydoc]

I had propane on my last truck. The propane is injected into the air chamber and is run off of the map sensor to tell it how much to put in. You can read more about it at bullydog.com and dieselperformanceproducts.com.

 

[Ozarker]

The problem is determining how much to use. The Army use to use propane as a cold starting aid as well but it was mounted on a device that let a pre-metered amount in when you pushed the button. Just enough to aid ignition but not enough to cause combustion and run the engine on its own.

You run into problems when someone is spraying unmetered amounts into the intake. Especially if someone is standing there spraying enough to make it actually run on the ether or whatever else you are spraying in. You can do some serious engine damage that way.

Diesel engine manufactures don't warn against using ether as a starting aid because it is bad for an engine. They warn against it because invariably some fool will keep spraying it in there to run an engine that won't keep running on it's own for some reason.

 

[kubmech]

Direct injection diesels can stand some ether to aid in cold starting, mostly if they were not designed with an alternative starting aid. But never use ether on an engine with pre-combustion chambers, which most of your compact diesels are running nowadays. The JD salesmen mentioned earlier says JD is direct injected? Hmmm, OK, maybe I've been away from the Yanmars too long, but many were definitely pre-combustion as I remember them. All the Kubotas that have been produced in say the last ten years plus are also pre-combustion (TVCC, three vortex combustion chamber). Basically combustion of the "pre-charge" happens in a very small area prior to "propogating" to the cylinder. This is the main danger of using ether in these engines. The cylinder head and pre-combustion chamber are not designed for this type of rapid expansion and can cause some major damage. Using WD-40 instead of bleeding properly is a pretty /w3tcompact/icons/cool.gif little trick, but I'd prefer to bleed the system properly. Many, maybe even all the engines I have rebuilt, do to cracked/broken rings and ringlands, cracked cyl. heads, blown out pre-combustion chamber caps, had a very distinct odor of ether in the air cleaner area, for what it's worth.