'72 350/200hp Idle Speed

[Kevin Morris]

Hello all. My '72 350/200hp 4-spd. is, as far as I can tell, bone stock. Does anyone know what the idle speed should be, when the engine is at operating temperature? It feels most comfortable at around 750-800, but is idling at around 1050 RPM right now.

Kevin #39927

[Patrick H.]

Re: '72 350/200hp Idle Speed

Is your TCS system operative or non-operative?

If it's working, and the solenoid on the right side of the intake does its job, it is around the 800 rpm mark (assuming you set it there).

If your TCS is bypassed or stuck open, and your distributor receives vacuum all the time from the carb, approx 1000-1100 would be correct.

Patrick

[Joe L.]

Re: '72 350/200hp Idle Speed

Kevin-----

The GM-specified idle speed for your engine is 800 RPM with an initial timing setting of 8 degrees BTDC. Other idle speeds and timing settings may produce more satisfactory engine operation. Make sure that it's set close to the above if and when you need to have your car emissions-tested, though.

[Kevin Morris]

Re: '72 350/200hp Idle Speed

Umm.....TCS ?

[Patrick H.]

Re: '72 350/200hp Idle Speed

Yes, TCS.

That wonderful, primitive emissions system on your motor.
I think I figured correctly in that yours is most likely missing. So much for originality.

Attached to the left front of your carb "should" be a solenoid which has certain functions. There should be a tan wire running just along the left valve cover, and heading towards that solenoid.

The part you're worried about is a switch-type solenoid with vacuum ports attached to the right hand side of your intake just inboard of the valve cover and lateral to the carb. There should be a stud holding it on. This solenoid allows (or doesn't allow) vacuum to reach the distributor. The vacuum line from the carburetor runs to the distributor by way of this solenoid. See it in the picture of my car in the link below.

Patrick




TCS on manifold

[George Romano]

No paint on inboard coil bracket bolt?

Just razzin ya Pat.
Got an extra thermostat housing to sell me?

George

[Edward McComas]

Re: '72 350/200hp Idle Speed

Patrick;

I notice that your passenger side valve cover has two wire clips on the inboard side. Is this valve cover original to the car? I think I understand that these base motor valve covers have been seen on original cars in many different wire clip configurations.

[Patrick H.]

Re: '72 350/200hp Idle Speed

Ed,

hahaha. Same pics you saw before.

Yes, while "most typical" is no clips, I've seen other examples like mine with two clips on the passenger's side valve cover. These covers are original to the car.

Patrick

[Patrick H.]

Re: No paint on inboard coil bracket bolt?

George,

I might have another thermostat housing, but then again we're not supposed to say that here. Maybe at another place that might be more appropriate.

Patrick

[george romano]

Says who?

You and I have been friends for years. Who's to say that I can't ask for a part for my car?
Anyway, I'll check you out at Carlisle.

George