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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,266
I think the CIS injector pintle only chatters between open and closed when it first starts to open and maybe at idle. During acceleration and at speed there is so much more fuel going through the pintle that it is held open by pressure and flow continuosly.
If it was chattering all the time then the fuel system pressure regulator in the head would also probably chatter open and closed all the time.
You can hear the pressure regulator in the fuel head sqweek a little as it chatters and equalizes against the fuel accumulator when first turning on the fuel pumps, if the engine is off and silent so you can hear it.

A garden hose nozzle makes it's conical spray pattern in exactly the same fashion as a CIS injector, and the adjustable pintle position in a garden hose nozzle is stationary while doing it.
A CIS injector may chatter open and closed a little at idle speed, but I'm sure it is open fully at higher speeds.
Old 03-14-2009, 09:11 AM
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