2013 Isuzu D-Max Pricing and Specs

Remapping an engine – done right – can provide you with more performance. But there’s also often a price to be paid in terms of reduced fuel economy and increased tailpipe emissions. Typically, there are workshops that are very good at this and others that aren’t so expert at extracting more performance.

But before you go down that route, it sounds like there’s something wrong with your vehicle in its current state. Fundamentally, a 2013 Isuzu D-Max should be able to haul a van of that mass, comfortably at the legal speed limit. That said, that’s a fairly hefty caravan and experience shows that many owners of similar rigs find that about 90km/h is a more comfortable speed for highway travel. So maybe you need to lower your expectations a little.

A full service and tune-up would be the first step in improving the towing situation, by returning all the engine’s settings to their stock position. Modern turbo-diesels can also suffer a fall-off in performance over time as the fuel system (pumps and injectors) wear, the diesel particulate filter becomes full of soot and the intake system becomes clogged with a mixture of soot and oil from the vehicle’s emission-control system. Those are the things we’d check first before shelling out for a remapped engine computer.

D-Max models before MY 17 do not have a DPF. The later Euro 5 compliant 4JJ1-TC engine does have a DPF filter.

It’s clearly frustrating you, but I don’t believe you’ve copped a lemon on the basis of what’s happened. Isuzu fixed the diff, end of story, they also replaced the first pump under warranty, again end of story. The issue is why have two pumps failed, and why didn’t Isuzu cover the second pump. These are questions I would be putting to Isuzu. I’m guessing that the second pump wasn’t covered because the warranty had expired after three years.