Diesel cold starts

While attempting to start a tractor on a 20- below-zero morning to feed cattle, I had to use the ether injection kit – only to discover that while repairing a broken hydraulic hose to the steering actuator a year ago, I accidentally allowed the small plastic tubing that carries the ether from the unit to the air intake manifold to fall and lay over the exhaust manifold.

Michael J. Thomas

Over the course of last summer’s use, the heat from the exhaust manifold burned a tiny hole through the tubing, allowing the ether to discharge into the air before reaching the intake manifold when I depressed the button to activate the unit.

Some cold fingers, badly applied electrical tape and a few less-than-choice words later, and I had the tractor running.

Robert Jensen, a mobile diesel mechanic located near Salmon, Idaho, says, “There are two lines of thinking when it comes to assisting the start of a cold diesel engine with ether. There are operators that will tell you that you should never use ether – the engine will become dependent upon ether, ether will shorten the life of the engine, etc.

While there is no substitute for warming a diesel engine before attempting to start it on a cold day, ether is actually a very good starting aid when applied correctly to engines that are designed for its use.”

Jensen explains that most of the older tractor engines will tolerate the use of ether, and many, such as John Deere for example, were designed with an injection port on the intake manifold. If you are unsure about your tractor, check the owner’s manual or talk to the dealer.

Two easily identifiable red flags against using ether are intake manifold heaters or glow plugs. If your tractor has either of these, DO NOT use ether to start the tractor. The preheater elements and glow plugs can ignite ether, potentially causing severe damage to the engine and possible injury to the operator.

Repairing an existing ether injection unit

Over the years, I have encountered several ether kits on different tractors that were not functioning properly and initially I thought I would have to replace the units. With the exception of one unit that was physically crushed, I was able to debug and repair all of the others.

Ether injection kits are very simple. When wired correctly, the units are activated by an electric solenoid that you activate by pressing a button on the console of the tractor during the engine cranking cycle of the ignition switch or key.

When the solenoid cycles, the canister discharges ether through a tube from the unit to the intake manifold for the duration of time you depress the button.

To troubleshoot the unit, start by removing the ether canister and make sure it is not empty or short of fluid. If you are unsure about the quantity of ether in the canister, replace the canister with a new one available at any automotive parts store.

Use a premium ether product. Some of the cheaper starting fluids do not contain enough ether to be effective for severe cold weather diesel engine starts.

If the unit still fails to function after ensuring the canister has sufficient fluid, enlist the aid of a helper to determine whether or not the solenoid is cycling. If the solenoid is not cycling when the helper presses the button during the engine cranking cycle, use a test light or multimeter to determine if you have power at the unit. Also, check the ground.

If you have power and a good ground, use WD-40 to free the solenoid. It is not uncommon for a solenoid to stick after years of non-use or exposure to dirt (in the case of a canister being removed and not replaced).

NOTE: The power source to the button on the dash should be the lead on the ignition/key switch that is live during the cranking cycle.

If the solenoid functions correctly but no ether flows to the intake manifold, the tubing to the intake manifold or one of the ports is plugged. Detach the tubing from the intake manifold and the injection unit and attempt to blow through it.

You may be able to clear the plug, but if not, the tubing is readily available at most auto parts stores. You will need to pick up new compression ferrules to fit the tubing at the same time. The ferrules from the original tubing will be compressed to the tubing – making it impossible to reuse them.

Installing a new ether injection unit

Once you have determined your tractor engine is designed to tolerate the use of ether, and you do not have an intake manifold preheater or glow plugs, locate a place to mount the unit that will not be in the way of accessing dipsticks or filters for engine service.

Next, route the ground and power wire in order that they do not conflict with moving parts or the exhaust manifold. Attach the ground wire to a good ground on the tractor frame or an engine bracket. Route the hot power wire from the ether unit to the console of the tractor. If you do not have a spare push-button switch in the console, you will need to install one.

Attach the hot power wire from the ether unit to one side of the push-button switch. Attach a wire to the opposite side of the push-button switch and route the wire to the ignition or key switch. Use a test light or multimeter to determine which lead from the ignition switch is hot only during the cranking cycle.

After disconnecting a ground cable from the batteries to prevent arcing, attach the wire to the lead on the ignition switch.

NOTE: Do not connect to a lead in the ignition that is hot at any time other than the cranking cycle. This will allow ether to only be injected as the engine is turning over and diesel is injected into the cylinders.

This allows for lubrication to the cylinders and pistons and also serves as a safety to prevent accidental ether injection into a hot, running engine.

Finally, carefully route the plastic tubing from the unit to the intake manifold to avoid moving parts and hot surfaces. Attach both ends with compression ferrules or fittings and the installation is complete.

Tips for proper operation of ether injection units

As Jensen explains, for the diesel engine rated for the higher pressures created by ether combustion without a manifold preheater or glow plugs, ether is not harmful when used correctly and in moderation.

Use the following method to safely use ether to assist in severe cold weather diesel engine starts:

Crank engine several revolutions allowing diesel to be injected into the cylinders. You should just begin to see a bit of smoke from the exhaust. Be careful not to crank too long and heat up the starter or run down the battery.
Quickly press the ether unit power button. Do not depress the button longer than two seconds to prevent excessive ether injection that can lead to ether lock or engine damage.
If the engine does not fire, depress button for another two-second burst.
If the engine fires but dies, repeat the process.