REBUILDING

Rebuilding instructions (Carter TQ)

Metering Rods and Jets Thermoquad

Adjustments

Bowl Vent Valve Thermoquad

Identifying Your Carter TQ

Thermoquad Specifications

CIRCUITS

Float Circuit Thermoquad

Choke Circuit Thermoquad

Idle Circuit Thermoquad

Secondary Circuit Thermoquad

Accelerator Pump Circuit TQ

TROUBLESHOOTING AND Q&A

Surging in the Thermoquad

Thermoquad Dies When Coming To A Stop

Hesitation or Bog on Acceleration TQ

Pump Cups Failing

Runs Lean / Starves for Fuel

Dies at stop Thermoquad

Repairing Inserts

OVERVIEW

The Carter Thermoquad has three main parts

• Air horn houses choke valve, air valve for secondaries, fuel inlet system (two floats and needle valves), accelerating pump system, primary boost venturis, vacuum controlled step-up piston, metering rods, and low and high speed fuel metering system
• Main body houses primary jets and is constructed of phenolic resin for cooler fuel temperatures
• Throttle body houses throttle valves and linkage

All TQ carburetors installed on vehicles equipped with an EGR system have a venturi vacuum port on the side of the carburetor. This is the only vacuum port located in the main body. All other vacuum pickup points are located in the throttle body.

TYPICAL CARTER THERMOQUAD (TQ):

APPLICATION