Setting the injectors on a Cat 3126A

Caterpillar 3126A timing issues



Our engineers have been working on an interesting engine in the workshop recently which I thought I’d share with you.

The engine in question was sent to us by a marine operator for a full overhaul: nothing out of the ordinary there.

The engine in question, however, IS out of the ordinary: A Cat 3126A with 2 valve cylinder heads and combined pump injectors.

Caterpillar only made a few of these engines, and thanks to various issues with timing, they discontinued the engine after a year and moved on to the 3126B with fully electronically controlled injectors.

After a full inspection, strip down and clean, it was time to reassemble with the overhauled components.

To set the injector fuel racks up, special tooling was manufactured in house, to compress the injector springs allowing them to make the adjustments.

Each injector rack was required to be set within 0.02mm of each other which required fine adjustments (this would be tricky to do on a vessel swaying from side to side!)

The maximum fuel setting for the rack was then set up using the special CAT tooling.

The set up required a fixture to be fitted to the cylinder head (see photo) using injector 1 as the datum.

Setting the injectors on a Cat 3126A

The engine has been tested with no issues, and once the gearbox is reinstalled, we will be installing the engine back on the vessel.

If you have any unusual or complicated issues you need looking at, let us know – our engineers love a challenge.

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