Quote:
Originally Posted by alexander
you want me to take a picture of my dad's intake manifold in his tdi, or will you just trust my word... they throttle air like any other car does....
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Not being able to see all the plumbing on my Tdi due to all the cosmetic plastic covers ,I cannot comment on this.
What I'm however sure of is the Mercedes Benz OM352 engine in my Unimog does not use a throttle valve to adjust engine speed. The air goes from the filter unrestricted into the inlet manifold. That is also true for all other truck (lowish tech) diesel engines I have seen. The speed of the engine is regulated by the injector stroke length, and therefore fuel volume of the mechanical diesel pump, a quite nifty and expensive little block of engineering I might add.
It might be different on the new electronic injector engines which I know has a lot of electronic control and sensors.
But then even though there may be a butterfly valve in the inlet track it does not mean that it is there to control engine speed. There are patents on the web where throttling of the intake air charge is proposed to reduce vibration, knocking and noise at idle speeds, yet power control is still done by way of injector timing (electronic injectors).
Sorry for being a little OT, but my 2c worth after having had to fiddle with a diesel that ingested water contaminated diesel ±200km from the nearest proper town.
BTW, I would love to get detail on the engine controls of modern diesel engines, if someone has a link.
