[echrisconnor]

Please bear with me. I've been working with my CIS system for several months now tying to chase down a hot starting issue. Throughout this process I have verified my assorted pressures many times over and have verified things are working properly and not leaking. My problem was the WUR as allowing system pressure to bleed down too quickly after a hot run (yes, the WUR, after many tests and a replaced check valve and fuel distributor system pressure O ring), which I disassembled, cleaned re-installed. The car now starts flawlessly when hot after one or two hours. It also runs like it always has -- fast and strong.

So, the problem now is that after a hot run, the next morning when I turn the ignition on the injectors start spraying as soon as the fuel pump goes on (I have my pump jumpered to run as soon as the ignition is turned on). I can hear them singing away, and they will continue to do so for about a minute as system pressure builds and the control plunger drops down. If I lift up on the metering plate while this is happening, there is no resistance, the plunger has sucked itself up to the top overnight. if I keep my hand on the metering plate I can feel the plunger coming down slowly -- all the while the injectors are squirting away flooding the engine. This didn't happen before.

So, what I'm thinking is happening is that after a hot run and several hours going by, one side of the plunger is either getting negative pressure, or positive pressure, and the plunger gets sucked up.

As a remedy, if I just flick on the fuel pump for a few seconds (with a cold engine) and then come back an hour later, the problem is gone. The system is re-pressurized and ready to go. It starts pefectly then.

Help. I thought I was tuned in to so many of the CIS problems, but this is a new one.