Why Your 2010 Mitsubishi Eclipse Keeps Stalling (And How to Stop It)

How to Fix Stalling

If your 2010 Mitsubishi Eclipse is stalling, you're not alone. This frustrating issue can stem from several specific causes, with a faulty 1G Cam Angle Sensor (CAS) being a primary culprit according to owner reports. The problem often involves incorrect parts, electrical gremlins, or failing components that disrupt the engine's vital signals. As one owner, Raider_831, highlighted a common frustration: "My question is do any of you guys know a good place/link to get them that will fit no issues. I know Autozone and O’Rillys will often give wrong parts." This guide will walk you through the symptoms, diagnosis, and repair based on real experiences from Eclipse owners.

Symptoms

Stalling in your Eclipse is rarely an isolated event and is usually accompanied by other telling signs. The most direct symptom is the engine cutting out unexpectedly, which can happen at idle, while driving, or when coming to a stop. This isn't just an inconvenience; it's a safety hazard that needs immediate attention.

Owners frequently report other sensory clues that point to the root cause. You might notice white smoke from the exhaust, which can indicate coolant burning due to a compromised head gasket or a cracked component, though it's less commonly the direct cause of stalling. A distinct burning smell, often described as electrical or oily, may accompany the stall, suggesting an overheated wire, a failing sensor, or fluid leaking onto hot engine parts.

The stalling event itself can feel violent or subtle. Sometimes, the vehicle will shudder or jerk before dying. Other times, it may simply lose power as if the ignition was turned off. Crucially, owners have connected these episodes to underlying issues like vacuum leaks (which create an unmetered air imbalance) or problems within the ignition and fuel systems, such as faulty injectors. As Raider_831 detailed during their diagnostic process: "My spark plugs look good, spark plugs wires look good and both aren’t old less than 1 year. So my next step is to test my injectors to see if they’re the issue."

Most Likely Cause

Based on aggregated owner discussions and repair experiences, the 1G Cam Angle Sensor (CAS) is a prevalent and likely cause of stalling in these vehicles. The Cam Angle Sensor is a critical component of the engine management system. It tells the ECU the precise position of the camshaft (and by extension, the position of the pistons), which is essential for correctly timing fuel injection and ignition spark.

When a 1G CAS begins to fail, it sends erratic or incorrect signals to the ECU. The computer, receiving bad data about engine timing, cannot properly command the fuel injectors or ignition coils. This leads to misfires, rough running, and ultimately, a complete stall as the engine loses its synchronization. The issue is compounded because many aftermarket or chain store parts are not always reliable fits or of sufficient quality for the Eclipse's specific requirements, leading to premature failure or immediate incompatibility.

How to Diagnose

Diagnosing a stalling issue requires a methodical approach to isolate the faulty component. You'll need a basic set of hand tools, a multimeter capable of reading resistance (ohms) and voltage, and an OBD-II scanner. While a generic scanner can pull trouble codes, a more advanced scanner or a platform like ECMLink (popular in the DSM community) can provide live data, which is invaluable.

Start by connecting your OBD-II scanner to the port under the dashboard. Check for any stored diagnostic trouble codes (DTCs). Codes related to cam/crank position correlation (e.g., P0340 - Camshaft Position Sensor "A" Circuit) are a strong direct indicator. Even if no codes are present, the problem may be intermittent. Next, perform a visual inspection. Look for obvious vacuum leaks by checking all intake hoses, the PCV valve hose, and the brake booster line for cracks or disconnections. Listen for a hissing sound while the engine is running.

If visual checks are clear, move to electrical testing. With the engine off, you can test the resistance of the Cam Angle Sensor if specifications are available in a service manual. More effectively, you can check for power and ground at the sensor's connector with the ignition in the "ON" position using your multimeter. Testing for intermittent failure is trickier; this often involves monitoring the sensor's live output signal with a scan tool while gently tapping the sensor or wiggling the wiring harness to see if the signal drops out, simulating the conditions that cause a stall.

Step-by-Step Fix

Replacing a faulty 1G Cam Angle Sensor is a manageable DIY job. Here is a step-by-step guide based on common owner procedures.

1. Safety First & Preparation: Park your Eclipse on a level surface, engage the parking brake, and disconnect the negative terminal of the battery. This prevents any electrical shorts or accidental engine cranking. Gather your new CAS, a set of wrenches or sockets (typically 10mm and 12mm), and your multimeter. Allow the engine to cool completely if it has been running.

2. Locate the Cam Angle Sensor: On the 4G63 engine (found in GS-T and GSX models), the 1G CAS is located on the passenger side of the cylinder head, at the end of the intake camshaft. It is a cylindrical component with an electrical connector and a shaft that slots into the end of the cam.

3. Remove the Electrical Connector: Press down on the locking tab of the sensor's electrical connector and pull it straight off. Inspect the connector for any corrosion or bent pins.

4. Remove the Sensor Mounting Bolts: There are typically two 10mm or 12mm bolts holding the sensor bracket to the cylinder head. Carefully remove these bolts and set them aside. As one owner, TortugaEclipse, cautioned about part fitment: "It says that it fits my car but idk if it’s my error or the part didn’t actually fit."

5. Remove the Old CAS: Gently pull the sensor straight out from the cylinder head. Be prepared for a small amount of oil to seep out from the opening. Have a rag ready to catch it. Note the orientation of the sensor and the alignment of the internal drive tang.

6. Install the New CAS: Before installation, compare the old and new sensors to ensure the drive tang is identical. Apply a thin film of clean engine oil to the O-ring on the new sensor. Carefully align the drive tang with the slot in the end of the camshaft and push the sensor firmly into place. It should seat fully without excessive force.

7. Reinstall Mounting Bolts & Connector: Hand-tighten the two mounting bolts, then torque them to specification (usually 14-18 ft-lbs). Do not overtighten, as you can crack the sensor housing. Reconnect the electrical connector until it clicks securely.

8. Reconnect Battery & Test: Reconnect the negative battery terminal. Start the engine and let it idle. Listen for any irregular sounds. The idle should be smooth. Take the vehicle for a cautious test drive in a safe area, monitoring for any recurrence of stalling or hesitation.

Parts and Tools Needed

• Primary Part: 1G Cam Angle Sensor (CAS). It is critical to source a quality unit. OEM (MD189305) is best, but reputable aftermarket brands from specialty DSM vendors are recommended over generic auto parts store units.
• Tools: Basic socket set (10mm, 12mm, 14mm), wrenches, flathead and Phillips screwdrivers.
• Diagnostic Equipment: Digital multimeter, OBD-II code scanner.
• Consumables: Shop rags, a small amount of clean engine oil for lubricating the new sensor's O-ring.

Real Owner Costs

The cost to fix stalling varies dramatically based on the root cause and who does the work.

• DIY (Cam Angle Sensor Focus): A quality 1G CAS from a specialty vendor can cost between $150 and $300. If you do the labor yourself, this is your total cost. As one owner seeking parts lamented, "My issue now is locating a replacement," highlighting the challenge of finding correct components.
• Professional Repair (Independent Shop): If you take the car to a mechanic, diagnosis time (1-2 hours at $100-$150/hr) adds to the part cost. A CAS replacement job might total $400 to $600, including parts and labor. If the issue is more complex—like an electrical short in the ABS system requiring wiring repair, as hinted in discussions about fuse locations—costs can rise to $800+.
• Professional Repair (Dealer): Dealership rates are higher, often $175/hr or more. The same CAS replacement could easily exceed $700. For complex electrical diagnostics, dealers may charge significantly more.

Prevention

Preventing stalling issues revolves around proactive maintenance and using quality parts. Always use reputable sources for sensors and critical engine components. Generic chain store parts have a high rate of failure or incorrect fitment for the Eclipse. Regularly inspect engine bay wiring harnesses for chafing, especially near sharp edges or hot components like the exhaust manifold. Keep the battery terminals clean and tight, as voltage fluctuations can cause sensor signals to go haywire. Address small problems immediately; a minor vacuum leak or a slightly rough idle can be a precursor to a major stalling event. Finally, if you modify your ECU, ensure all wiring and sensor conversions are done correctly. As Colin rosti mentioned regarding an ECU swap: "I drive a 1995 Eclipse GSX I bought a 1997 Eclipse non EPROM ECU with ECMLink installed," underscoring the need for precise compatibility in modified systems.

What Owners Say

Real experiences from MITSUBISHI owners:

Owner Experiences

"My question is do any of you guys know a good place/link to get them that will fit no issues. I know Autozone and O’Rillys will often give wrong parts." — Raider_831 (source)

"My spark plugs look good, spark plugs wires look good and both aren’t old less than 1 year. So my next step is to test my injectors to see if they’re the issue." — Raider_831 (source)

"You must be logged in to view this image or video. Here’s where the fuse is shown in the circuit diagram, between fusible link 8 and the ABS Power Relay." — 19Eclipse90 (source)

FAQ

Q: How long does it take to replace a Cam Angle Sensor? A: For a competent DIYer with the right part on hand, the physical replacement of the CAS takes about 30-60 minutes. However, the total time should include diagnosis to confirm it's the culprit, which can add another hour. If you're troubleshooting from scratch without a clear code, budget 2-3 hours.

Q: Can I drive my Eclipse if it's stalling intermittently? A: No, it is not safe. Stalling can occur without warning while driving, leading to a complete loss of power steering and braking assist. This creates an extremely dangerous situation for you and others on the road. The vehicle should be towed or driven only directly to a repair facility if the problem is very mild and predictable.

Q: Is stalling a common issue on the 2010 Eclipse? A: Based on owner community discussions, stalling is a reported issue, often linked to specific failing components like the 1G CAS, electrical faults, and vacuum leaks. It is a known problem pattern rather than a universal defect, but it is common enough that there is a well-trodden diagnostic path within the owner community.

Q: DIY vs mechanic—what's recommended for this fix? A: If you are mechanically inclined and the diagnosis clearly points to a sensor like the CAS, it is a very approachable DIY job. The steps are straightforward. However, if the problem is intermittent, involves complex wiring (like the ABS system circuits owners discussed), or you are unsure of the diagnosis, a mechanic is recommended. Electrical diagnostics require experience and proper tools. As 19Eclipse90 noted while helping trace an ABS issue, consulting detailed factory service manual diagrams is often essential: "Here’s where the fuse is shown in the circuit diagram, between fusible link 8 and the ABS Power Relay."

Q: What if the new part doesn't fit? A: This is a frequent headache, as owners have reported. If the new CAS (or any part) doesn't fit, do not force it. Double-check the part number against OEM specifications. Return the incorrect part and source one from a specialized DSM performance vendor or the dealership. Using the wrong part can cause further damage.

Q: Could a bad battery cause stalling? A: Yes, indirectly. A weak or failing battery can cause voltage drops that make sensors operate erratically and can reset the ECU. While not the most common direct cause, it's a fundamental check. Always ensure your battery, terminals, and charging system are in good health when chasing electrical gremlins that lead to stalling.