Originally posted by Lonnie
Yes, it needs to be energized (closed circuit) to port the vacuum and hold them closed. Then de-energized (open circuit) to release the vacuum and allow them to open.
I'm confused and need a little clarification. Usually the only time a solenoid is activated is when it needs to change from it’s “steady” state to the alternate (least used) state. In other words, its "normal" state (open electrical circuit, no current flow though the coil) is the state that it’s in “most of the time”. Then when it needs to open or close (depending on the design of the solenoid, normally open or normally closed) something either provides voltage or ground (depending on how it's wired). That way there is only current flow during limited times and not all the time which saves heating the coil and also wear on the small springs internal to the solenoid.
So you’re saying that during normal cruising, while the IMRC’s are being held closed by vacuum (ported through the IMRC solenoid), the EEC is providing a ground and thus energizing the solenoid coil? Then at 3000, the EEC removes ground and the solenoid de-energizes and the IMRC’s “snap” open due to the flat springs on the IMRC runners.
Isn’t that backwards from the way most solenoids are wired?
Don’t get me wrong, I’m not questioning you. It just seems like that is backwards from the way most solenoids are wired. I haven’t researched the IMRC’s yet, but I just assumed that when de-energized, they would pass the vacuum to the IMRC’s and they would stay closed, then at 3K, the EEC would energize the circuit and close (or vent) the vacuum and the IMRC’s would close by the springs.
Any guesses why Ford would have current flow through the EEC when it’s not necessary?
Oh wait, I’m trying to comprehend Ford engineers. My bad!
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