DavidFeygin
09-30-2001, 11:36 AM
I have had this problem since purchasing the car and have been battling the problem for over a year. I have run out of ideas.
The problem: when accelerating moderately or aggresively, the car seems to buck slightly one or two times under 2500rpm in all gears. Although, the problem is more noticeable in 2nd gear, and almost not at all noticeable in 1st gear (don't know why, except maybe that there is less resistance in 1st gear.) The problem seems to be a little worse for the first few minutes of driving when the car is cold.
What I've tried: New 02 sensors, new pressure regulator, new plugs and wires, there don't seem to be any vacuum leaks, there doesn't seem to be any un-metered air coming in (although who can be positive).
I tried looking at the 02 sensors directly, while they were connected and while they were disconnected from the ECU. While connected, the sensors jump around all over the map (0.1-0.8 volts), but the engine seems to respond to a too lean or too rich condition. When you rev the engine (with no load) the voltage seems to drop initially below 0.1 volts and then come back to 0.7 or so. While the sensors are disconnected, when you rev the engine, the voltage stays below 0.1 volts and never comes back up. So, I'm thinking that although the engine is responding properly to the 02 sensors, there is something wrong with the initial settings/mixture. Maybe the air-mass sensor is out of spec? I'll try to check it later.
Any and all ideas appreciated,
thanks for your time,
dave
The problem: when accelerating moderately or aggresively, the car seems to buck slightly one or two times under 2500rpm in all gears. Although, the problem is more noticeable in 2nd gear, and almost not at all noticeable in 1st gear (don't know why, except maybe that there is less resistance in 1st gear.) The problem seems to be a little worse for the first few minutes of driving when the car is cold.
What I've tried: New 02 sensors, new pressure regulator, new plugs and wires, there don't seem to be any vacuum leaks, there doesn't seem to be any un-metered air coming in (although who can be positive).
I tried looking at the 02 sensors directly, while they were connected and while they were disconnected from the ECU. While connected, the sensors jump around all over the map (0.1-0.8 volts), but the engine seems to respond to a too lean or too rich condition. When you rev the engine (with no load) the voltage seems to drop initially below 0.1 volts and then come back to 0.7 or so. While the sensors are disconnected, when you rev the engine, the voltage stays below 0.1 volts and never comes back up. So, I'm thinking that although the engine is responding properly to the 02 sensors, there is something wrong with the initial settings/mixture. Maybe the air-mass sensor is out of spec? I'll try to check it later.
Any and all ideas appreciated,
thanks for your time,
dave