Technical Misfire then power drop but recovers

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Technical Misfire then power drop but recovers


New member
Apr 6, 2010
Just returned from the French Alps and had some issues. In cruise control at 85mph in my 2.2 Ulysse Prestigio and experienced an intermittent missfire. Not enough to knock it out of cruise control initially though. Then it dropped out of cruise control and I was unable to accelerate back up to speed. Maintained 50 mph for a couple of miles before pulling in to service station. Idling was fine and I had no error messages. After refuelling (I was only half empty) set off with jolty acceleration but made the remaining 50 miles or so to Calais. By time I arrived in Calais it seemed much better but then being allocated the "up ramp" eurotunnel it simply didn't have the power to go up the ramp. Had to reverse everyone back off so I could take the low level entry. Departed Eurotunnel and drove 200 miles home without incident. Seemed to be accelerating well and no more misfire. To me it was like fuel starvation. The fuel filter was replaced about 15,000 miles ago when serviced but I have heard that French diesel can be "dirty" - seems a bit odd to me. The car has over 160k on. Any comments as to what the problem is/was? Many thanks.
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Had a diag done today and it showed up an error on pressure. A smoke test revealed that the lower secondary throttle unit was leaking so looks like that's the problem.