Posted by chriscase on Thursday, February 22, 2007 at 23:39:00 :
In Reply to: Re: Spark Plug Air Pump posted by Tim Holloway on Thursday, February 22, 2007 at 22:30:46 :
The body of the one I had used a piece of rolled gasket paper as a check valve. It allowed ambient air to get pulled into the cylinder, then shut under pressure so the compressed air flowed up the hose. Since the other cylinders were sucking air through the intake manifold, the cylinder in question would pull in ambient air instead of fuel-rich charge.
I haven't seen one in years. Those little 12v air-shock compressors replaced them.