I have a 1994 Honda Concerto 1.5l gasoline car, fuel injected.
When the engine is cold there are no accleration problems. But once it warms up it stutters if I step hard on the gas.
When it does this is only stutters until it reaches a certain RPM (around 2500-3000), then it abruptly stops stuttering.
The stuttering happens only when the car is moving. It does not happen when the car is parked.
It does not stutter if I accelerate slowly, but over time it's been getting worse. It's getting harder and hard to climb a hill.
The stuttering is even.
The stuttering happens in all speeds.
The last time X was repaced:
- plugs: 2 years (20000km) ago, and the old plugs looked fine. Current plugs look good.
- wires: never
- cap: five years ago, it had a crack in it which led to starting problems when it was humid.
- wires: never, but I did the check-the-wire-is-sparking test when I was troubleshooting the problem that led to the cap replacement and the wires behaved normally
- rotor: never
- coil: never
- Emissions testing (in France, which is C02 at least): recently passed.
- O2 sensor, recently replaced. I was getting a vague code and the mechanic's guide's troubleshooting said to try replacing the O2 sensor. This made the codes go away and abated the problem somewhat, but not entirely.
- Fuel filter, replaced one year ago. Previous filter did not seem particularly dirty and it was there for several years.