dallasite21

I have this little magnetic arm that connects to my throttle linkage and bolts onto the carb. It looks like it is supposed to control the idle someway. I beleive it is broken, but I dont know what it is called or what it does. Does anybody know this info. I have attached a pic showing the area it is in. Its a 71' cutlass 2 barrell 350 by the way.

Lady72nRob71

Hi Parrish,
I am thinking that is an anti-diesel solenoid. When ignition is on, plunger is extended, setting the throttle to idle position. When key is turned off, plunger retracts, throttle closes less than idle, and cuts off airflow so that dieseling / run-on is prevented or reduced.

dallasite21

I think its functioning inproperly... it causes the car to idle high because it is pulling on the throttle.

delmontcrusier

that can be related to vacum lines if they are cracked broken or missing the engine will race at least that was the problem on one of my vehicles.

gearheads78

Idle compensator for when the A/C is on?

Lady72nRob71

Do you have an ohmmeter? Ohm it out to see if the coil is good and make sure the plunger moves in and out freely. If those both work, then trace back to what is supposed to be controlling it.

joe_padavano

Correct.

It should not be "pulling" on the throttle. It should simply be a stop that the throttle arm comes to rest against. The solenoid should be energized at all times that the key is on and retracted when the key is off.

Oldsguy

To elaborate on Joe's statement. If your idle is too high because of the device, then just re-set your idle speed according to your tune-up specs, the device isn't really causing a high idle, a mis-adjustment is.

Bluevista

I don't believe that is stock for a '71?, it should have a manual dashpot for anti-stall according to the manual.
Either an anti-diesel or an AC compensator as said. My '71 Vista Cruiser has the same engine and carb and my idle really drops when the compressor kicks in, an AC idle compensator wouldn't be a bad idea, maybe they had a dealer retrofit because of the problem?

My '68 poncho 400 has the anti-diesel solenoid stock and you adjust the plunger with a small/ignition wrench in or out after it's warmed up and off the choke, it looks just like your deal.

jensenracing77

i think we have some confusion here. (maybe just me and not we) on these cars i only seen the A/C cars have it for idle compensation. when the A/C is on it pushes on the throttle to compensate for the drag of the A/C compressor. i thought that the anti dieseling came later.

Bluevista

I know the anti-diesel solenoid is stock on my '68 GTO. The manual dashpot on the Olds is an anti-stall device used so the carb doesn't close too quick and stall the engine when you let off the gas suddenly as far as I know. I don't know when they started using the idle compensation deal for the A/C, didn't some cars older than '71 have them?
I know nothing about A/C but it seems like on the later units than mine the compressor cycled on and off along with that idle compensating solenoid you would hear clicking when the idle speed went up or down with the compressor cycles. The book just shows a higher idle setting for A/C in the book for mine. The 1971 6 cylinder has the C.E.C. valve on the carb and an anti-dieseling relay tied in with the A/C wiring, maybe it also increases idle speed with the AC on?