Recently bought a 2001 sprinter 313cdi on 120k and been having a few problems, some of which I have allready resolved with help from this forum. It had only done about 1000 miles in the last year and was overcooling and lacking a bit of power when I got it so checked it over and found a couple of problems with the injectors. Replaced one and reseated another and tested and replaced the thermostat at the same time. After this it went perfectly for just over 100 miles, warmed up quickly to about 85deg c and had plenty of power as you would expect for this engine. It then suddenly seemed to lose all boost and power and started limiting revs to about 2.5 to 3k ( though this was not consistant., sometimea it was higher or lower. Once it seemed to go back to full power and pulled about 4k coming out of a corner in second but this only lasted very briefly) Turbo is also behaving strangely. If the revs are kept constant at the limiter then you can occationaly hear the turbo winding up and then releasing in a cycle but there is no change in rpm or power delivery and no boost. This must be the variable geometry actuator going in and out I guess but not sure why it would be doing this. If the engine is turned off and restarted it is the same and after leaving it overnight it was the same in the morning. There is no dash lights on at all and never has been. ( the test lights do all come on at startup) This van has no egr, no dpf, and no cat so can't be any of the usual problems on the later vans. Only other weird thing is that the water in fuel light was lighting up occationaly at high revs. I drained the filter it and there seemed to be no water present. After this the light was still coming on sometimes (so i put this down to a faulty sensor) and there was a very slight ticking coming from the filter which I assumed was some air trapped somewhere and went away after a few miles. The water in fuel light kept illuminating though right through to when it lost power. (It now can't rev high enough to light it up.) Vehicle looks well serviced. Oil is clean and obviously pretty fresh and air and fuel filters. Look to have been recently replaced. Only other things I can think of is that while I was checking the injectors after reseating them a small scrap of tissue got sucked down the intake manifold into cilinder 1. This make a banging noise for a fraction of a second then smoked out the exhaust then went back to normal. Van worked perfectly after this. One other thing is that when I was searching for causes of the lack of power I put a can of Wynn's turbo cleaner through just after ihe filter box. (This had solved a lack of power issue on my old transit) I later read in the Haynes that the engine should never be run without the filter attached because the turbo is very sensitive to dirt. I feel Haynes is often over paranoid but thought I should mention it. Any ideas anyone? Its got me stumped? Going to take it to n a fault code reader next week if I can't figure it out but I don't want to drive it again if at all possible. Its dog slow and its really hilly around here.