Air Shrouded Injectors (and low boost)

Mike_Buckham at Mike_Buckham at
Thu Feb 20 13:08:26 EST 2003


I have some questions relating to the air shrouded injectors on my 1989
200qt, 1B engine (UK spec) which I haven't found answers to in the archives
or on the web (including SJM Auto-Technik).

1. Where does the air which is forced into the head around the injectors
end up? Is there an exit port somewhere?

2. Is the restrictor in the tube from the intake manifold to the head a
one-way valve? If so, I presume it only allows air into the head?

3. How much boost would I lose if the restrictor was missing?

4. What effects would it have if I removed the air tube from the intake
manifold to the head and blocked up the intake manifold port? Would it
adversely affect the injectors?

One of the reasons for these questions is that I am not getting sufficient
boost at the moment and the air restrictor is currently missing. I have the
lower hose to the bottom of the wastegate diaphragm plugged, so the
wastegate should not be opening. As I drive along and I should be getting
lots of boost, I can actually hear quite a lot of air being forced out. It
sounds like it is coming from the wastegate (as it sounds close to the
bulkhead) but is this actually possible if that bottom hose is plugged? I
can't find any air leaks in any of the tubes.

Thanks for any help,

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