JCB 3CX won’t start after sitting in barn

boom&bucket

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Sep 10, 2025
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I just took a 3CX out of storage where it's been sitting in a barn for a year. It cranks up nicely, but it won't start. The fuel system appears to be dry. I'm on the lookout for some tips on bleeding or any common problems people face with the Delphi pump.
 
@boom&bucket you're right, the air needs to be purged.
Start at the fuel filter, there's usually a small hand pump on the side of the filter housing that you can use to prime it.
Once you've got fuel flowing out of the bleed screw on the filter, work your way up to the injection pump.
You'll likely find another bleed screw there.
and the final step is to crack open the injector lines on the engine while you crank it to get any last bits of air out.
 
Make sure to take a look at the lift pump too. If it’s a mechanical one and has been sitting dry for a year, the diaphragm might be stuck or even cracked. This could prevent it from supplying the system properly before it even hits the filter.
 
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