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1971 LT-1 with factory carb. Unable to use choke spring as it forces butterfly plate to remain closed after engine is warm. This is an after market piece. Not sure where to turn. Help!!!!
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Originally Posted by 1971 LT-1
1971 LT-1 with factory carb. Unable to use choke spring as it forces butterfly plate to remain closed after engine is warm. This is an after market piece. Not sure where to turn. Help!!!!
Some thermostat springs unwind UP and some unwind down, you have the wrong spring.
Factory carb on a 71 LT1 is a 780 CFM Holley 4150, not a Qjet. I would replace the thermostat coil that opens the choke when warm. The vacuum pull off opens the choke a little upon engine start up and then manifold heat to the thermostat coil opens it the rest of the way as it warms. This is a simple and very reliable system and if yours is not opening it has to be the thermal coil, or possibly binding in the linkage. My LT1 had an issue with the choke not fully closing when cold that I eventually solved by slightly bending a link that was binding so ensure all links move freely.
From: At my Bar drinking and wrenching in Lafayette Colorado
The choke coil for the Holley-equipped cars rotates opposite of the Q-Jet choke coils. You have the wrong choke coil for your Holley application - you have a Q-Jet coil (or, you have a blocked manifold exhaust crossover).
I've attached some Pics. The unit I purchased was supposed to be for the LT-1. This looks just like the link that Mrvettenick shared. Choke plate closed Choke plate open Unit I purchased, Looks just like the one in the link that Mrvettenick shared Carb Info Overall view
It appears that either that rod is too long, or the choke spring is incorrect. I'll take measurements fully open and closed later.
I have a '70 and the lever hook up is at 9 o'clock, not 3 like yours. I didn't think there was a difference in the years.
Last edited by Mrvettenick; Jul 14, 2021 at 11:23 AM.
That is the same part that I currently have. As you can see by the pictures, it doesn't line up with the hole. I'm baffled. Any help would be appreciated.
I looked at the pictures of the other 1970 LT1 that I owned in the past and it had the same rectangle shaped choke spring cover as the pictures I posted, BUT the 1971 and 1972 LT1 are different and use a choke spring cover as you show.
Also, as Lars stated, you probably have a Q-jet choke spring. The 1971 Holley spring is different.
Use the Docrebuild catalog to see what you need. Docrebuild's E-Commerce Web Site - Search
Thanks for checking, but this unit is not the correct one for the LT-1.
Toylman posted a link for Doc Rebuild showing the exact same unit that I have.
As stated previously - now I'm really confused.
Thanks for checking, but this unit is not the correct one for the LT-1.
Toylman posted a link for Doc Rebuild showing the exact same unit that I have.
As stated previously - now I'm really confused.
Based on your pictures the choke coil has to pull the rod down as it heats up.
Does it pull the rod down?
Choke issue
