First, I am so glad I found this site. Thanks.
I have been reading a lot about mTDI set ups and still have a few questions that may be obvious but the answers have escaped me.
Background...I have a lot of experience with jet boats and gas engines. I understand EFI and have rebuilt engines. I have had an ALH in a 99 bug that I worked on so I know the basic architecture and the basics of eTDI. Some basic assumptions I have may be totally off base so feel free to get simple with me.
1. do the injectors work like a gas injector where there is a gate that opens and closes or are they just a nozzle? If they are just a nozzle why are they so expensive? and if they are gated like a gas injector why does the injector pump meter and time injections? and what tells them to open and close?
2. Why not use a waste gate and BOV to control boost when using a VVT and discarding the computer? then just leave the turbo at what ever level you want to or even a lever that allows you to adjust it for optimal performance at the current driving conditions.
3. Am I missing something or are there more parts to the mTDI set up. Right now all i can see as parts are the:
a. engine...consisting of block, head, pistons, valves, cam, manifolds, oil pump, etc...mechanical stuff to move the air in and exhaust out.
b. Turbo...either VVT or WG BOV controlled
c. Injector pump and plumbing to supply fuel
d. Mechanical water pump and cooling system.
e. Front of engine stuff turned by belts off the crank...waterpump, alternator and injector pump
All of these things are individual systems that don't talk to each other and the only connection is the timing belt and moving air. No sensors tell one system to do something different because of another systems status. Basically no sensors or wires of any kind any where other than the alternator, starter motor, and shutoff valve.
Is this correct? I seriously feel like I am missing something. The injector pump is a complicated mechanism but other than that...
Thanks, Matt.