This is general q, infact for a nissan CD17 diesel, ok heres the thing.
This certain nissan sunny diesel revs weird, Ive marked off the throttle lever and measured the rpm increase, about 25% throttle and the rpm would increase like 500 rpm, about at halfway I would be seeing 2200 revs and at WOT the engine would climb to the 4600 rpm redline, Its more like you have to drive WOT all the time.
while my VW revs crazy, just think about throttle and the engine goes nuts.
any ideas what causes this - the nissan techs say its supposed to do that, then I show them the Golf - that why does this engine rev so nasty?
btw Ive checked the Compression 500 psi on all cyls, and timed the incredibly (bi***y) nissan timing mark arrangment and separate IP belt, all are super, pump is 0.9mm (just like the factory manual says), starts up ultra quick with just 10 seconds glow in the morning.