okgsds

I was looking at my engine bay tonight and noticed this part off of the carburetor and it was not connected to anything. Looks like it should be though.. Can anyone tell me what it is? I am about to order an assembly book and shop manual so hopefully these will help me in the future.. Thank you in advance..

TimAT

That is the idle stop solenoid. IT's job is to kick the idle up a bit when the A/C is on.

okgsds

Ahh i see i see, well seing how the AC is not hooked up nor working, guess I do not need to figure out where the heck the connection that goes to it is missing at or where it goes.. thank you for the info on this.

Peterbuilt

I agree, that is the idle stop solenoid but on my 74 is it only energized with the A/C turned on or is it energized with the key in 'run' and then used to fully close the throttle with the key off to prevent run on? PG.

KapsSA

One of the green wires in your other post goes to it, single connector.
Comes out of the harness near the compressor.

okgsds

AHH.. Man I cannot wait to get those assembly and shop manuals..

avner

Hello
I don't want to highjack this thread it the same subject
Where I can buy this module?
I want to add it to my Carburetor Holley 4150 (HLY-0-80783C), But I can bolt in what is in the market.
Thanks
Avner

OK, I found it HLY-46-74.

okgsds

Yeah that wasn't it. Not nearly long enough to reach.

Phil Zell

This is a very good item to have if you are not running a choke setup. You can manually switch it when engine is cold for a fast idle.

TopGunn

Well, that's actually an anti-dieseling device as Pete pointed out. It was originally designed to engage whenever the ignition was on and bump up the idle to the desired level. Then when the ignition was turned off it collapsed and closed the throttle blades 100% to prevent the engine from running on after the key was off. But it works Excellent as an idle boost when the A/C is turned on, that's how I have mine hooked up. Been using it several years for that.

CCrane65

There isn't enough power in the solenoid to move the linkage by itself. You have to energize the solenoid then press the accelerator slightly to allow the plunger to extend.

cc

CCrane65

TopGun, when you aren't running the A/C, doesn't your engine idle about 100-150 rpm high?

cc

TopGunn

No, you wire the solenoid to the clutch on the A/C compressor. When the clutch pulls in it energizes the coil. As you just pointed out, after one bump of the throttle, the lingage will now rest on the plunger. If you're already off idle going down the road it works without doing that.

Bill

...Roger...

I could be wrong but when I see a tan wire going to the solenoid its usually an anti-dieseling solenoid controlled by ign on and if the wire is green its a compressor kick up.

CCrane65

Roger, I think some of these guys have found a new use for the ISS. I guess if you don't have a dieseling problem may as well put it to good use.

I couldn't do it. Mine used to diesel like crazy before I added the ISS.

cc

sxr6

In my old 74 I used mine to pick up the idle when it was in gear.
Low comp & solid lifter cam & it didn't want to idle in gear & if you picked up the idle rpm it rev'd to high in neutral.

There was enough power in mine to pick up revs without touching the throttle