about 2 months ago, whilst driving along, the engine suddenly lost power. I could not go above 30mph with my foot to the floor. I stopped and switched off for a couple of hours. On starting up again the engine was fine and all power was restored. All was well until 2 days ago when the same thing happened again, power lost but the engine kept going. I again turned it off and after a while, started the car and everything was fine and has been since. Any ideas please?

John Taylor, April 2011

So this is where it gets weird... 6 weeks ago, the alarm decided it wasn't friends with the radio any more with no way of re-entering the code. The radio went back to Clarion, who fixed it, and hey presto, since then the cutting out has ceased completely.

So it looks like an intermittent fault in the security department of the radio was influencing the immobiliser to cut engine power. Is this even slightly plausible? BTW, if you say no, you have to offer a more likely explanation!

Johnny Five, April 2015

Update: it did it again this week. Revs would not go over 2000, even in neutral. As before it had been running normally for some while, and then developed the condition. Like last time, pulling over, switching off, waiting 5 mins and back on again cured the problem. Unlike last September, the fuel tank was almost full, and I hadn't negotiated any sharp bends, so the fuel starvation theory now looks pretty unlikely.
Does anyone know if there's a ECU reduced power mode that it might have fallen into? Cycling ignition off and on would (I guess) reboot the ECU and clear the error.

Johnny Five, December 2014

Not an answer, really, but to add to the conversation... I run a 2.2dCi Tino, and I had very similar symptoms this morning; no amount of throttle got me over 2000rpm in any gear. I pulled over and waited 10 minutes to think about this, restarted and the problem was gone. Possible causes: (1) Overheating, self- clearing after a cooldown break? possible but not likely, temperature gauge normal throughoput the event (2) software glitch, cured by reboting? can't positively discount this (3) my favourite theory, fuel starvation caused by air entering fuel pickup. I had low fuel level - the yellow light had just come on - and I had just done a right turn at a roundabout, so maybe the fuel sloshed away from the pickup momentarily, allowing a air bubble to enter the fuel line. After a 10 minute break, the air bubble found it's way to a harmless place (fuel filter maybe) and all was well again.

Do any of these explanations sound plausible to anyone?

Johnny Five, September 2014