I have a 2006 7fgcu20 that will only stay running at higher idle. anything over 1/4 throttle it will run very smoothly but letting off slowly to ideal idle it will chug bad like its loading up. I have checked the main and slow solenoids on the regulator and both reacting perfectly. the injector, map sensor and slow solenoid are recently new also. In this case I would think it is the diaphragm in the regulator but here's the catch... while running the check engine light flashes as if following injector pulse or ignition timing. when u let off the gas and it dies, the slow solenoid is clicking. Both the slow solenoid and the start fuse have 4.5 volts at it? i am a little confused at the flashing CEL and these weird voltage readings. if anyone has any info it would be greatly appreciated.