Ford Transit / Lucas DSA947 goes into limp mode under load

Hello,

Perhaps someone has an idea about what might be causing the following error.

Ford Transit Diesel, manufactured in 1994, 2.5-liter turbodiesel.
with an 'electronically controlled' fuel injection pump, type Lucas DSA 947.

I'm having a problem where the car exhibits this behavior when driving on the highway at certain speeds.
approximately over 100, and only if you drive at that speed for about 10 minutes or longer.
enters its emergency mode. The fault light for the motor electronics is illuminated.
A Ford workshop read a fault code 61, supposedly indicating a defective fuel injection pump.

The error never occurs when driving on highways, not even over months.
Ford is stuck and can't find a solution, except for the suggestion to replace the pump.

The engine delivers excellent performance and has reasonable fuel consumption, and it runs perfectly.
Normal daily operation, but not under constant, high-load conditions like those experienced on a highway.

Does anyone have any ideas?

Thank you in advance. Best regards from the Palatinate Forest, Thomas.

Even if this doesn't really help you, given the symptoms you described:

"The engine has excellent performance and reasonable fuel consumption, and runs perfectly."
"Everyday operation, but not under constant, high-load conditions like you'd find on a highway."

"I would simply live with it and save the money that would be spent on fixing the issue. Otherwise, it's worth checking: electrical connections, diesel filter, (upper and lower) hoses, the turbocharger air intake system, and possibly also the timing belt replacement interval, etc."

Best regards,