Why Won’t My Tractor Start (Part 2)

If you have already read the first installment of “Why won’t my tractor start?”, you know that we discussed some initial troubleshooting areas including the ignition switch, battery, and starter. In this edition, we explore the scenario where air has found its way into the fuel system of your diesel tractor.

Diesel engines are notoriously difficult to get running after air is introduced into the fuel lines. This is generally caused when the tractor runs out of diesel fuel. Therefore it’s very important to take precautions when performing long or fuel-intensive tasks—it’s always better to walk back and get more diesel than to chance running out.

Getting Air Out of Your Chinese Tractor Fuel Lines

When air gets into the system, the fuel lines (which rely on high amounts of pressure to force the injectors to “pop” open and spray diesel during the combustion stroke) will not be able to build the necessary pressure. To get the tractor running again, you have to prime most of the air out of the lines, which can be difficult and time-consuming. We want to reiterate that this can easily be avoided by staying aware of fuel levels and keeping a flashlight handy so you can check the tank.

However, now that air is in the system, it will have to be bled out to get the tractor running again. The first thing to do in this situation is to fill the fuel tank. The extra weight of the fuel will help to push the air out of the lines when you begin to prime the system. Locate the bleeder bolt on the injection pump; the location of this screw varies from pump to pump, but it will be a small, flat head bolt that you can back out a bit to bleed the air. Once the air is bled and fuel runs raw from the bleed bolt (not bubbling), tighten it back down.

Bleeding Air from the Fuel Lines

Now move on to the hard lines (pictured on right) which run off of the injector. Slightly loosen the lines at the compression fitting and crank the engine with the transmission in neutral, using ten-second intervals until fuel runs raw from the loosened lines. Then tighten the lines up; the engine should turn over and start.

This process should get the air primed out and allow the engine to start running again. Don’t be alarmed if there is some white smoke coming from the exhaust on the restart; this is common with diesel engines. Although this is a straightforward process, it can be more difficult than it appears—so always keep a diesel can close.

​​If you're having trouble with this issue and need further assistance, please contact us for help. And remember that Circle G has fuel system parts and more tractor parts you need for your JinmaFarm ProNortrac, and more Chinese tractors!