recurring problem with old XC90 - advice on finding a diagnosis

I bought a 2008 Volvo XC90 from a small dublin dealer 3 years ago. It’s an old car and we weren’t expecting not to have the odd old-age issue along the way.

We had issues with injector-related issues right from the start. Every 3 months or so there would be a reduction in engine power and the car would light up with faults before eventually switching to a type of “limp-home” mode.

In fairness to him, the dealer did take it back to repair it, giving a courtesy car along the way. Repairs would take 6-8 weeks sometimes.

sometimes all that was required was a new injector and we’d be on our way.

overall there were 5 services at the dealer before the most recent series of breakdowns.

we’ve had it in with a local mechanic and then a main dealer. Again failed injectors. The most recent stop was to replace the engine loom (!) and the problem piped up again within 3 weeks of such a major service.

The main dealer says there’s no indication of a reason why the problem keeps coming back, but you know, it keeps coming back.

I need to get a second opinion from a true Volvo specialist who might actually recognise this issue. I’m looking for a reference to a dealer or independent/Volvo expert mechanic who can help figure this one out.

the second hand market is miserable for decent used cars and we want this one to last another year or two without roadside assistance.