Warm-up Regulator

Fits:
Porsche 911 SC 3.0L 1975-83
Having problems starting your 911 when it's cold? It could be the warm up regulator located on the upper left hand side of the engine. This simple device is responsible for controlling the amount of fuel delivered to the engine during its warm-up period. The pressure acting upon the top of the control plunger varies depending on the engine temperature and provides an effective method of enrichment. The control pressure is tapped off from the primary pressure circuit in the metering head's lower chamber through a tiny restrictive hole which gives it the ability to differentiate between the two pressures. A flexible pipe then connects the control plunger gallery to the warm-up-regulator and returns back to the metering head to a connection next to the primary pressure regulator's transfer valve. This valve is in the circuit to close the fuel from the control circuit when the engine is off, avoiding the total loss of system pressure while the engine is stationary.
- The surcharge for this reconditioned part will be refunded when the exchange unit is received and approved by us and the relevant manufacturer.
- Please note, surcharge refunds often take an average of 6 to 8 weeks to be approved by the manufacturer.
- Acceptance of the exchange part is at the manufacturer's discretion, based on the part being fit for reconditioning.
- All surcharges and exchanges are subject to our terms and conditions.
PLEASE NOTE:
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
PCG606105JX
The product you are viewing cross references to these numbers
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 928 4.5L 1978-82
- Porsche 928S 4.7L 1981-83
High-Quality Warm Up Regulators for Stable Fuel Pressure and Smooth Cold Running
A warm up regulator—also known as a control pressure regulator—plays a vital role in mechanical fuel injection systems, especially in K-Jetronic setups. It adjusts control fuel pressure during the engine warm-up phase, ensuring the mixture is rich enough for smooth starting and gradually leaning out as the engine reaches operating temperature. This helps stabilise idle, reduce hesitation and deliver consistent driveability in both cold and warm conditions.
For classic and performance-focused vehicles using mechanical injection, a properly functioning warm up regulator is essential for clean running, fuel efficiency and smooth throttle response.
What Warm Up Regulators Do
Warm up regulators manage fuel pressure and mixture during
engine start-up and warm-up. Their key functions include:
- Regulating
control pressure to refine the air-fuel mixture
- Providing
enrichment during cold starts for smooth ignition
- Stabilising
idle speed as temperatures rise
- Improving
throttle response by optimising fuel delivery
- Supporting the entire mechanical injection system
- Reducing emissions by managing mixture transition during warm-up
They ensure the engine runs cleanly across temperature variations and adapts fuel delivery precisely during the early running phase.
Why Warm Up Regulators Commonly Fail
Due to their mechanical and temperature-sensitive nature,
warm up regulators can degrade over time. Common failure causes include:
- Internal
contamination from debris or aged fuel
- Blocked
fine passages reducing fuel flow
- Electrical
heater element failure preventing proper warm-up transition
- Corrosion
within the regulator body or pressure diaphragms
- Vacuum
leaks causing incorrect mixture adjustment
- Age-related
wear affecting control pressure accuracy
- Hardened seals or diaphragms leading to inconsistent operation
Symptoms of a failing WUR include hard cold starts, rough idle, hesitation, poor fuel economy, excessive richness and flat acceleration.
Why You Should Replace a Faulty Warm Up Regulator
Replacing a worn warm up regulator with a high-quality, precision-engineered alternative designed to meet original performance standards ensures your mechanical injection system operates as intended.
Benefits include:
- Reliable cold start enrichment
- Smooth transition to normal operating mixture
- Stable idle and reduced stalling
- Improved throttle response and overall driveability
- Restored fuel economy and emissions performance
- Protection for other fuel system components
For classic and performance vehicles, a correctly functioning WUR is essential to achieving consistent, reliable engine behaviour.