Why does my Mitsubishi Eclipse buck, surge or feel down on power?

Short answer: On a first-generation Eclipse that bucks and surges, one owner chased fuel, wiring and transmission fluid before a mechanic's scan found a bad crank position sensor, which on that car is built into the distributor, so the whole distributor was replaced. For any Eclipse that suddenly feels slow, get the codes read for free at a parts store before buying parts.

Symptom: The car bucks and surges, especially going uphill or on the highway, or it suddenly feels like half the engine is missing.

What to check first

1. Get the codes read at a parts store, and write down the exact code numbers.
2. Check fuel pressure under load, not just in the driveway. A member said pressure while climbing a hill can be very different.
3. Look over the intake snorkel and hoses for splits that only open up under load.
4. Check maintenance basics: air and fuel filters, plugs and fluids, especially on a high-mileage car with unknown history.
5. Ask a shop to check the crank sensor signal if the bucking comes and goes.

Likely causes

1. Crank position sensor (inside the distributor on the 1991 1.8L). The confirmed fix in the 1991 thread; the sensor isn't sold separately, so the distributor gets replaced.
2. Low fuel pressure under load. Members' first suggestion for surging.
3. Split intake hose or vacuum leak. Can leak only under certain loads.
4. Misfire or overdue maintenance. Common on high-mileage cars with no records.

What it usually costs

The 1991 owner said the dealer wanted about $700 for the distributor, while they found a new one online for just under $110. Labor is extra, so get a quote.

Is it safe to keep driving?

Short trips are usually okay, but surging or sudden power loss in traffic is risky. A flashing check engine light means a bad misfire; stop driving and get it checked. Verify with a mechanic.

DIY or shop?

DIY for reading codes, checking hoses and basic maintenance. Swapping a distributor is a moderate DIY job if you mark its position first; otherwise a shop can do it quickly.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists these recalls touching this area of the Mitsubishi Eclipse: 07E055000 (1995-1999 model years, fuel system, gasoline); 89V128000 (1990-1990 model years, electrical system); 96V158001 (1995-1996 model years, fuel system, gasoline); 99V333001 (2000-2000 model years, electrical system). Check your VIN at nhtsa.gov/recalls. If your car is part of this recall, the dealer fixes it for free.
• NHTSA complaints: 171 keyword-matched complaints for Mitsubishi Eclipse 1990–2000 (of 1,468 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-25; keywords: surge, buck, hesitate, power loss, stall, misfire, rough, crank sensor, distributor). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 91 Mitsubishi Eclipse Surging & Bucking on Car Talk, a 1991 Eclipse 1.8 automatic bucked and surged, mostly under load. Members suggested checking fuel pressure under load and looking for split intake hoses. After months of trial and error, a mechanic's scan found a bad crank position sensor inside the distributor; the owner replaced the distributor and reported months later that the bucking was gone.
• In 2000 Mitsubishi Eclipse GT v6 power loss on Car Talk, a 2000 Eclipse GT 3.0 with about 206,000 miles felt like it was running on three cylinders, with the check engine light on. Members said to start with maintenance and get the codes read for free at a parts store, and one Eclipse owner said a cylinder misfire that bad is something you'd clearly feel.

Quick tip

That 1991 owner spent months fixing other things before a real scan found it. Pay for a good scan early; it's cheaper than guessing.

Vehicle focus: 1990–2000 Mitsubishi Eclipse, mainly the 1990–1994 1.8L and the 2000 3.0L V6.

Safety / mechanic note

Sudden power loss while merging or passing can cause a crash. Verify with a mechanic.