Why does my engine management light come on when I drive 30 - 40mph in my 2008 Honda Civic 2.2 i-DTEC?

My 2008 Honda Accord 2.2 i-DTEC hesitates and surges when I drive 30 - 40mph, eventually resulting in the engine management light coming on. The Honda garage diagnosed low fuel pressure and changed the air filter and fuel filter but it didn't cure the problem. It's now back in and has had an injector fuel return pressure regulator and the fuel pump changed. It's still not working, can you help?
What they have done is cheapest fixes first. I would guess that the fuel pump they changed was the low pressure fuel tank lifter pump. What remains is the very expensive high pressure fuel pump.
Answered by Honest John on

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