this is very intresting as ive got exactly the same problem with my 208cdi , it looses power but if i turn it off and then bump it back up its fine again , did 300 miles the other day and it dident play up once , then just poped up the town and it happend 5 times , ive replaced all the bulbs, brake light switch, fuel fillter,checked all conections, got my head spinning
Same problem with my 413 CDI only I have had Mercedes change out one at a time the following trying to remedy the situation at there recomendation over the past 14 months.
1) fuel filter 2) Fuel Pump 3) Brake light Clusters 4) Brake light sensor switch 5) Wiring harness to Sprint Shift 6) Sprint Shift Pump 7) Turbo Charger.
Now they say to change the complete gearbox. I asked OK what is wrong inside the gearbox? they replied we dont Know!! but it will illiminate another possibility! I thought what a great idea, next time I stubb my toe I`ll ask the Doctor to cut my leg off!! These are Mercedes Top Mechanics, but at last I have found the solution, for this I am eternally grateful.
ANSWER (this is the one, it will solve all your problems as it did mine).
SELL your piece of GERMAN CRAP and NEVER EVER EVER BUY ANOTHER ONE.
Mine does pretty much the same thing. It's a 2000 308cdi, now with 175k, but started about 125k. As has been said it can go for hundreds of miles with no probs, then 5 times in 20 miles. Turning the key off and back almost always resets it.
I have noticed that the most common time for it to happen is when starting to overtake on a dual carriageway, and the car I'm about to overtake suddenly pulls out and I take my foot off the gas. When I put my boot down again, half the time there is no power there and I pull back to the inside lane to do the key stuff.
I run lightly loaded all the time so it's not struggling.
I had just about given up when I remembered this forum.
My 97 312d model done this for a year and no mechanic could tell me why someone says your injectors are blocked someone told me something else but coundnt get to the bottom of it.you will now laugh at what im going to tell you I coundlt start van one morning kept spinning no diesel coming up so i got a fairy liquid bottle a piece of rubber tube put some diesel in the bottle took the feed supply from the tank or so i thought and tried to crank the engine a few times nothing then cranked again and boom the was a bit of an explosive bang i ran round front of van the bottle had exploded diesel everywhere i had put it on the return pipe by mistake to the bottle well i thought thats done it i put the return pipe back on and cranked the engine and vroom the engine sprung into life and went very quiet purring like a cat now bearing in mind i had the timing done new belts pump looked at nothing worked untill the fairy bottle and the van has run great ever since tall tale i hear you all say the engine light went out and the van has run great ever since it wheelspins not trying pulling away.
there are many things that can put the engine into safe mode, needs to be put onto a diagnostic and monitored, the none start and fix with a washing up bottle could be the pressure regulator valve o rings,