Engine runs at high RPM idle on hot starts

[Brave76]

I have a quick question somewhat on topic. My 440 always starts right up when cold. But if run and even let idle till it warms up and I can kick off the choke. But if I dont drive it or only drive it a few minutes. And turn it off then try to restart it within about 10 minutes later, without setting the choke or anything, it will start right up but at a very high RPM and no amount of playing with the gas or driving it makes it stop. Like if I put it in drive and apply not gas pedal it will maintain 20mph.

[DaveVA78Chieftain]

Do you still have the original Thermoquad installed or has it been replaced with a Holley or Edlebrock carb?  Different mecahnisms on each carb type.

Dave

[Brave76]

Good question. This is my first vehicle that  is not Fuel injected. Even my 78vws all have had FI. When I go look this weekened will there be markings on the carb that I can tell the difference with the different models?

[DaveVA78Chieftain]

Original Thermoquad has a black plastic body (base) with 2 large secondaries and smaller primaries (reffered to as spreadbore)

Thermoquad uses a heat tube choke.
Adjustments are located in the Dodge service manual.

Edelbrock is an aftermarket replacement.  Also requires either a spreadbore to square adaptor plate or a new manifold.

Edelbrock either has a manual (cable) or an electric choke depending on what was purchased when they replaced the TQ.
Adjustments can be found at the Edlebrock web site.


Dave