Idle solenoid
- Thread starter Mikke H
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Ranger16
Well-Known Member
"Idle solenoid"? Are you talking about the anti-diesel solenoid?
What engine, what year?
What engine, what year?
6 pack or?.......
dla4567
Well-Known Member
Ranger16 called it an “anti-diesel solenoid”.
My understanding is that when you shut down it allows the carb to close tight to prevent engine run on, or “dieselling”. They must have had a problem with this back in the day. Mine did it when I first got my engine running but not since it has been tuned properly.
There is probably someone on here that knows more about it than I do.
My understanding is that when you shut down it allows the carb to close tight to prevent engine run on, or “dieselling”. They must have had a problem with this back in the day. Mine did it when I first got my engine running but not since it has been tuned properly.
There is probably someone on here that knows more about it than I do.
66Satellite47
Well-Known Member
The solenoid was part of the "package" Chrysler used to deal with emissions standards. The fuel calibration of the "Six Pak" was set to deal with those standards. I found on each of my 6 BBL carb combinations that a main key to drivability was removing the idle adjustment plugs on the end carbs and enriching the idle mixture a bit. Idle improved, transition to end carb improved, no need for the idle solenoid at all.
It can also be hooked up through the distributor vacuum advance stupid system. The vac advance goes five degrees advanced and activates the solenoid. If you have that advance on the car you will definitely know it.
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Gentlemen,
My '70 GTX is an original V code car and has a fully functional "anit-diseling" solenoid. It is energized (plunger extended) all the time the ignition is "on". It was part of the Cleaner Air Package (later called Cleaner Air System. Due to ever increasing emission requirements (lower CO & HC components of the exhaust), OEM carb jetting is leaner, static spark advance is retarded, and thermostats are calibrated for a higher operating temperature and idle RPMs are higher. All of these things contribute to the POSSIBILITY of engine dieseling on shut down. The purpose of the solenoid was to close the carb throttle valves on sundown eliminating the after run possibility.
Because of the cam I use (Crane equilivant to the Mopar 292 degree 0.509 lift purple shaft at 4 degrees retard) the engine idles at approximately 1200 RPM and +15 degrees static timing (35 degrees total @ 2400 RPM) I need the anti diesel solenoid energized at idle for a reasonably smooth idle. I experience NO dieseling at shutdown. I use the OEM Prestolite dual point distributor. The choice to use the solenoid as intended or not, is up to you. Just be glad you do not have the air injection system, a belt dfiven air pump and associated plumbing.....a real PITA (pain in the ***).
But...this is just my opinion.
Bob Renton
To Halifaxops.... the distributor solenoid shown in your posting RETARDS the static timing approximately 5 degrees thru the insulated connection on the carb's hot idle screw....just thought you might like to know.....BR
My '70 GTX is an original V code car and has a fully functional "anit-diseling" solenoid. It is energized (plunger extended) all the time the ignition is "on". It was part of the Cleaner Air Package (later called Cleaner Air System. Due to ever increasing emission requirements (lower CO & HC components of the exhaust), OEM carb jetting is leaner, static spark advance is retarded, and thermostats are calibrated for a higher operating temperature and idle RPMs are higher. All of these things contribute to the POSSIBILITY of engine dieseling on shut down. The purpose of the solenoid was to close the carb throttle valves on sundown eliminating the after run possibility.
Because of the cam I use (Crane equilivant to the Mopar 292 degree 0.509 lift purple shaft at 4 degrees retard) the engine idles at approximately 1200 RPM and +15 degrees static timing (35 degrees total @ 2400 RPM) I need the anti diesel solenoid energized at idle for a reasonably smooth idle. I experience NO dieseling at shutdown. I use the OEM Prestolite dual point distributor. The choice to use the solenoid as intended or not, is up to you. Just be glad you do not have the air injection system, a belt dfiven air pump and associated plumbing.....a real PITA (pain in the ***).
But...this is just my opinion.
Bob Renton
To Halifaxops.... the distributor solenoid shown in your posting RETARDS the static timing approximately 5 degrees thru the insulated connection on the carb's hot idle screw....just thought you might like to know.....BR
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