340 thermoquad hard starting

-

dancinwulf

Well-Known Member
Joined
Apr 8, 2015
Messages
101
Reaction score
15
Location
Ketchum Idaho
My 340 starts immediately once running but is hard to start when cold, is there a choke that can be fitted or is there any tricks I can try.
 
It should have a choke that closes when you push the gas pedal to set it when you start it cold.
 
Here are the views from both sides
 

Attachments

  • 340 carb.pdf
    312.1 KB · Views: 122
  • 340 Choke.pdf
    645.9 KB · Views: 103
Here are the views from both sides
It has a choke butterfly and some linkage but no chole coil in the intake to close it when cold. You may need to get a Factory service manual to find all the needed parts and adjustments. PS, loading photos directly to the site is quite easy and much more convenient for us.
 
Here are the views from both sides
Just a couple keystrokes and I found this. You can see what you are missing. It would be smart for you to check the number on the intake and carb to make sure they are compatible with the choke pieces you will need. If you have a mish mash of parts it will be a lot tougher to come up with the right combination.

thermoquad.jpg
 
I think Quadrajet Parts has an electric choke conversion that bolts onto the manifold like the original one does.
 
That should do it. A TQ needs to have the choke close to start cold.
Yep, it's not like a Holley that squirts a couple shot glasses of gas with every stomp on the loud pedal. :lol:
 
I've been using them for a long time. They haven't worked well, take forever to heat up. You need to use that little resistor thing called the choke control. The power wire plugs into the choke control and the choke control plugs into the choke wire. I'm sure it will work like Chrysler intended then. That Tomco one doesn't have the wire but the factory ones and the Carter ones do. The part number for the choke control is 3755770. The early mechanical TQ chokes that used a gasket below the well cup always seemed to work better for me.
That should do it. A TQ needs to have the choke close to start cold.
 
I've been using them for a long time. They haven't worked well, take forever to heat up. You need to use that little resistor thing called the choke control. The power wire plugs into the choke control and the choke control plugs into the choke wire. I'm sure it will work like Chrysler intended then. That Tomco one doesn't have the wire but the factory ones and the Carter ones do. The part number for the choke control is 3755770. The early mechanical TQ chokes that used a gasket below the well cup always seemed to work better for me.

You are correct in that they don't heat up quickly, but not all of them were electric, either. The elarly TQ cars didn't have the electric assist. I was trying to choose the most economic option. Those electric ones are pricey.
 
The early mechanical TQ chokes that used a gasket below the well cup always seemed to work better for me.


Especially the ones whose choke well is actually open to the exhaust cross over. Those really work well.
 
You are correct in that they don't heat up quickly, but not all of them were electric, either. The elarly TQ cars didn't have the electric assist. I was trying to choose the most economic option. Those electric ones are pricey.

That one is perfect. There was a truck choke that is not electric, I always used the truck one myself. I'll try and look the Chrysler number up later.
 
I ran a TQ for years without the choke, from -40 to 90* above, had to pump the thing about 40 times on cold days and feather it for few minutes once she did fire.
 
I also ran a TQ for years. Set it up right, it ran like fuel injection from -20 to 100+. Do it right and forget about it.
 
I ran an open element air cleaner year round, only had a problem once. Froze up on a really cold night on the highway
 
-
Back
Top