High idle, or maybe stuck throttle and hugely loud revving noise at start.

[John H.]

get a can of Carburetor cleaner and WD-40

[Keyair]

Robert, I looked closely at the picture, with my best eye, and I think its ok... the larger spring goes around the back of the smaller one, and gets lost in view, but seems to come around and join in the right place.

Sarah, you said that when you pressed the gas pedal, the arm returned "slowly"... slowly is not always good... it shoud be directly linked to the gas pedal... only the last little bit of movement maybe slow because some carbs have a damper on the throttle arm that just slows the movement down for that last little bit like one of those door closers.
Please look again for us, and snap the gas pedal down a few times and see if it works smoothly and a connected kinda way?

Is it me or does that extra arm we assume is for the CC look non stock?

Also, the new noise is a worry.
It did occur to me this morning that pumping the gas pedal on these engines pumps gas into the engine, as it acts as the cold start choke... maybe the smell was the engine burning that excess fuel off....
.
Can you tell us again what happened when the engine made the big noise again at the start?
We are assuming that the throttle was stuck open, but how long did it run like that?

This new noise...
Was it deep kinda clunking noise that you feel as much as hear?
Did you guys see or notice the Oil Pressure gauge readings?

[ROBERT CROSS]

Key,

I think your right on the spring both ends do seemed to be attached properly.

But the noise is another concern, too bad we can't hear thru the cyber-web.

A metallic rattle (flex-plate) could be a lot better than a "knock".

Bob

[Keyair]

Yes, it looks ok.

I had a rethink while you were posting your last comment and had time to edit my earlier post...

Going from cold start to full throttle may have hurt something...

[ScrapIrony-2]

A 454 requires at least two and often three pumps before it starts...the noise is a concern that needs addressing...pull off the doghouse(WHY is it called a doghouse???) and see if you can locate the source of the sound...m

[John H.]

Purchase a can of Carburetor cleaner and WD-40

[Keyair]

Maybe an English phrase, but my guess would be its called a Doghouse on Airstreams because the Husband spends a lot of time in it....

[mnmhays]

Loud rattling noises are never good. Most of my idle issues have been due to bad cables or broken return springs. The scariest one was in my old Ford diesel pickup...

[crazeevw]

question? ScrapIrony says the 454 requires 2 to 3 pumps of accelerator to get the engine started. What if 454 has the Throttle Body fuel injector carb? Anyone here have the TB carb?

[ROBERT CROSS]

No pumping needed with TBI.

[Keyair]

I have a 1987 Suburban with a 454, and TBI, and had not started it for 3 months... Put the battery back in, turned the key and it started first time!
It has been 80deg here for the last 3 months tho...

[vswingfield]

Originally Posted by crazeevw

question? ScrapIrony says the 454 requires 2 to 3 pumps of accelerator to get the engine started. What if 454 has the Throttle Body fuel injector carb? Anyone here have the TB carb?

Others are correct. Shouldn't have to pump.

Not to mention, fuel injection is not a carb (short for carburetor). Different altogether.

[ROBERT CROSS]

But it sure looks like one.....your forgiven.

[John H.]

I press the throttle to set the choke.
let off the throttle peddle and never touch again until I am ready to drive off. after engine warms to temp & idles at 600 rpm

turn the key and it starts instantly each and every time.

If I pump the foot peddle I am screwed. Fuddled.