In article _EOdg.194434$P01.165735@pd7tw3no,
Private wrote:


AFAIK the 91-94 SOHC engines used a single electric injector mounted in the
throttle body. The 95 and all DOHC engines use one injector per cylinder
located in the port close to the valve, however while this is called
sequential port injection the injectors pulse once per revolution (@60
degrees BTDC) or twice per cycle so are actually pulsing on both the intake
and exhaust cycle. It seems counter-intuitive to me, but it works well so
the Saturn engineers must know something we don't. The ignition is also a
waste spark type that simultaneously fires two cylinders, one near the top
of the compression stroke and one near the top of the exhaust stroke.



Your engine is multiport but not sequential. Seq-multiport inyection fire
each injector individually and only when the valve is open. It improves
idle and part throttle economy. At medium to high loads injector are
open most of the time anyway, so when they open is not as critical
so the advantages of sequential are not important..



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Eduardo K. |
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