Re: Any choke on this panel control box?
The below information is a copy and paste from the TKS service manual, and explains how and why it works.
Turn Key Start: Theory of Operation
The TKS system has been added to carbureted engines to:
? Provide additional fuel to air mixture when starting a cold engine. Idle speed is slightly
increased by supplying the additional fuel / air mixture required to start a cold engine.
? Prevent enrichment when starting a warm engine.
COMPONENTS
1. The TKS carburetor casting allows starting fuel to be drawn from the float bowl and
mixed with air in a chamber. This enriched mixture is drawn into the engine through an
opening in the carburetor body below the throttle plate.
2. The TKS module mounted to the carburetor. When 12V DC is applied, the TKS module
will warm internally, causing a plunger to extend from the module and close the
enrichment fuel air passage in the TKS carburetor.
3. On 3.0L engines, an oil pressure switchprovides a ground (-) path for the TKS module.
Positive (+) voltage is continuously supplied through a 20 amp fuse directly from the
engine circuit breaker.
4. On V-6 and V-8 engines an existing oil pressure switch provides 12V positive (+)
voltage to the TKS module. Ground for the TKS module is continuously supplied.
TKS SYSTEM OPERATION
The TKS Carburetor assembly provides precise fuel and air delivery during startup for all
temperature conditions. An electrothermal valve, the TKS module, is installed on the
carburetor assembly.
Before startup and according to ambient temperature, the TKS Module brass sleeve
retracts, and the enrichment fuel and air valve is opened.
The TKS fuel / air passage is normally open, allowing fuel enrichment mixture through the
carburetor continuously, unless the passage is blocked by the plunger of the TKS module.
With the key switch in the start position, the vacuum of the engine pulls the enrichment fuel
and air into the intake manifold.This starts an electrical warming of the module.
With the circuit completed, the electrothermal TKS module brass plunger extends to block
the enrichment passage.
Once the TKS module brass sleeve is fully extended, the enrichment fuel and valve are
fully closed, and enrichment stops.
In order to keep the TKS module warming and the starting channel in the carburetor closed
when engine is warm a second circuit has been added. For additional information, see the
"Typical Starting System Components" in Section 4A for your particular engine type.
TKS Starting Characteristics
On 3.0 L models - If the engine has not run for a long period of time, it might require a
couple of attempts while the fuel bowl refills. Once the engine has started, it will idle at
700-900 RPM.
On 4.3 L, 5.0 L, and 5.7L models - If the engine has not run for a long period of time, it
might require a couple of attempts while the fuel bowl refills. Once the engine is started, it
will idle around 650 to 700 RPM in idle stabilization mode. If the idle exceeds 700 RPM,
the ECM adds spark, thinking that the operator is trying to accelerate, which could cause
the engine to idle at 700-900 RPM. After the TKS module has shut off the enrichment circuit,
the carburetor will function like a standard carburetor. If the engine is out of idle stabilization
mode, (engine below 700 RPM), you will hear and feel a slight drop in RPM. After the TKS
module has shut off the enrichment passage, the carburetor will function like a standard
carburetor.
