1971 LT-1 Choke Issue

[Alan B.]

I'm having an issue with the choke linkage. I believe I have the correct parts, but nothing lines up as expected.

[Bret S.]

Re: 1971 LT-1 Choke Issue

It looks like your choke rod going to your manifold heat spring is reversed.

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[Alan B.]

Re: 1971 LT-1 Choke Issue

Hello Bret,

When I try to install it either way it forces the butterfly closed. Is it possible to see how your spring is wound? The pic's I see online match what I have. As you can see in my pic's, the rod extends way above the hole it needs to go into. When I connect the rod through the hole the tension applied by the spring then forces the butterfly closed. The only other thing I can think is the spring is wound the wrong way. I've attached a pic of what I have.Coil Winding.jpg

Thanks for the pic.

[Bret S.]

Re: 1971 LT-1 Choke Issue

A couple of things to consider, being new, I would expect your setup to close the flap when at room temperature. My spring is old enough to join AARP and it closes the choke when cold, to about a 1/4" gap to the air horn. Also, the rod that connects to the flap itself (shown by the screwdriver) plays a role on how far the flap moves toward the air horn. Notice on mine, the angle that the rod is in relationship to the plastic fast idle cam. The more the angle is away from vertical, the less travel of the choke flap. And the top section of that rod will also affect how much it moves the flap. You may have to bend it slightly to get the proper travel. I tried to get a picture of the inside of the choke stove. Notice the end of the rod that engages the spring is horizontal, facing the front of the car and yours, is straight up. You may have to preload it a little.

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[Bret S.]

Re: 1971 LT-1 Choke Issue

You also have the choke pull off which will also act on the flap position based on engine vacuum.

[Alan B.]

Re: 1971 LT-1 Choke Issue

I think I have the wrong coil spring. I've seen others that look like they would work as needed.
I'm going to order a new 1 and will update.
Thanks for the pics.

Al

[Alan B.]

Re: 1971 LT-1 Choke Issue

OK - Now I'm at a loss for words. I found the exact unit I have on Doc Rebuilds site. It is identical to mine. Does anyone have a pic of the coil spring with the cover off from a functional car. I know its a long shot but I'm not sure where to turn now.

Thanks,
Al

[Terry M.]

Re: 1971 LT-1 Choke Issue

OK - Now I'm at a loss for words. I found the exact unit I have on Doc Rebuilds site. It is identical to mine. Does anyone have a pic of the coil spring with the cover off from a functional car. I know its a long shot but I'm not sure where to turn now.

Thanks,
Al

Alan
I know that the choke coils for the Holley and the Rochester operate the opposite. One pulls and the other pushes. What I don't know is which operates which way. I have delayed posting in the hopes that someone else would know that detail.

[Gary B.]

Re: 1971 LT-1 Choke Issue

Attached is a photo from my 72 LT-1. 71 and 72 are the same. I know this car is correct.

The choke rod pushes up to set the choke for Holleys.. Quadrajets choke rod pulls down to set the choke.

Hope this helps.

Gary B72_LT-1_Choke.jpg

[Peter M.]

Re: 1971 LT-1 Choke Issue

Alan,
This is from the 67 service manual. The choke coils are different in the way they mount but operate on the same principles as the newer coils.
The all V8 except 327-275HP and 350-295HP include holleys.
The 327-275HP and 350-295HPIMG_0787.jpg are quadrajets.