can someone explain the vortec fuel injection to me?

[John Redcorn]

I've never owned any sort of truck until a few weeks ago (99 Z71 Tahoe! it's awesome!) all my friends have always had chevy trucks since I was a teenager and I always thought the reason I never saw injectors on their motors was because it was throttle body injection.

I see now that some of the earlier ones used tbi but now it uses some central sequential thing.

Can anyone explain to me how this is really differs from the "normal" type FI-system? (like on an LT1, 3.8, ls1, 5.3 truck motor etc)
I'm not having any problems just curious. (and not looking forward to problems)


I know the injectors are called poppet valves and they squirt into each intake runner just like normal but why the spider instead of a rail outside the upper manifold? why poppets? what are they? why is it all enclosed in the upper manifold? is any of this advantageous in any way?


oh and I saw this, I think on another forum. gm extended the warranty on vortec central sequential fi to 10years 200kmiles but maybe just in california. The people on whatever forum I saw this at I think were saying they replace your intake manifold up with a vortec 5.7 marine manifold with 8 standard injectors and regular-ass fuel rail.
http://www.arb.ca.gov/newsrel/nr021103.htm

 

[DefEddie]

Basically it is CSFI injection,which is Central Sequential Fuel Injection.

Underneath the big plug behind the throttle body are 8 centrally mounted injectors.
They are the actual injectors that are fired by the computer.The injectors are sitting in a little cluster,each injector has a plastic tube running from it to an individual intake runner.
At the end of the tube is a black plastic clip and a small poppit injector. It clips into a hole into the intake runner,with the small poppit valve spraying into intake stream for the corresponding cyliner.
The action of the central injector firing causes the poppit to actuate under the pressure.

The new replacement injectors have an actual small injector in place of the poppit valve.