Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
ROCHESTER Models 2SE & E2SE 2-Barrel: Description
The Rochester Varajet Carburetor models 2SE and E2SE are 2-stage, 2-barrel downdraft carburetors. The primary stage consists of a triple venturi with a 35 mm bore. The secondary stage has a 46 mm bore and is equipped with an air valve with a single tapered metering rod. Both are equipped with integral, electronically-activated chokes, a choke vacuum break diaphragm and an idle speed solenoid. The 2SE model is used on American Motors Federal models.
The E2SE model is used by General Motors with the Computer Command Control system. The E2SE model is used by American Motors with the C-4 or Computerized Emission Control (CEC) system. The E2SE model is equipped with an electrically operated mixture control solenoid. The mixture control solenoid is mounted on the air horn and extends into fuel bowl. Fuel metering is controlled by the mixture control solenoid plunger opening and closing the fuel passage to the main metering jet.
When the plunger is in the down position (lean), fuel metering is controlled by a factory-adjusted lean mixture screw located in the float bowl. When plunger is in the up position (rich), additional fuel is metered to the main fuel well through the factory-adjusted rich mixture screw located at the end of the fuel supply channel in the float bowl.
Air is also metered by the plunger and is further metered by an idle air bleed screw (adjustable on American Motors, fixed on General Motors). The system constantly monitors exhaust gas oxygen content and other engine conditions to adjust air/fuel mixture accordingly.
All General Motors models are equipped with a Throttle Position Sensor (TPS) to electrically signal the ECM of throttle position. The ECM then "holds" the last known air/fuel mixture ratio or activates the mixture control solenoid to adjust the mixture as needed.
On American Motors models with A/C, an Idle Speed Solenoid (ISS) is used to maintain idle speed during A/C operation. All General Motors models are equipped with an Idle Speed Control (ISC) motor. The ISC is controlled by the ECM to maintain idle speed under all operating conditions.
All General Motors carburetors are equipped with a temperature regulated pump system with a thermostatically controlled by-pass valve. The by-pass valve is permanently pressed into the air horn. The by-pass valve contains a bi-metal snap disc that opens and closes the valve according to engine temperature. When closed (cold engine), pump delivers fuel to primary bore at full pump capacity. When open (warm engine), part of the fuel is returned to the fuel bowl. The by-pass valve is an integral part of the air horn and is not serviceable.
All carburetors are equipped with tamper-resistant features: factory-adjusted rich mixture screws (except General Motors), factory-adjusted lean mixture screws, riveted choke coil housing and hardened steel pump lever. All models are also equipped with idle mixture screw plugs.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.