Quote:
Originally Posted by massmike
Still hoping for some help here. I made the following changes but still have a slight surging while in closed loop.
-Replaced the O2 sensor with a new Bosch 11027 (This is the same as I previously had)
|
Follow my recommendation above:
Quote:
|
Originally Posted by AndrewCologne
However, when using a narrowband sensor, I strongly recommend switching to a 3-wire version with an integrated heater (BOSCH part number 0 258 986 502).
|
Quote:
Originally Posted by massmike
-Removed the test pipe in the exhaust and replaced with catalytic converter. (The cat only has a single cell in it, the other two were removed by a previous owner)
-Noncontact temp gun shows cat at approximately 500 degrees F at idle.
-Verified duty cycle at idle, set to 50-55% (I noticed the DC is much more stable at idle and easier to adjust)
-Verified O2 senor voltage at idle, swings from .1-.9Vdc
-Drove the car and monitored Duty cycle and O2 voltage. Duty cycle swings from approx. 46% - 60%. O2 voltage swings from .015 -.8Vdc
|
With an initial CO setting where idling results in a 50–55% duty cycle, it should normally fluctuate around 38–45% while driving — but not 46–60%, as that range is too wide and is exactly what causes the surging or pulling effect.
Quote:
Originally Posted by massmike
I am still getting a surging at constant loads, light throttle, and slow driving (parking lots).
Any thoughts on what to look at next? Again, surging goes away when system is in open loop.
|
First, try the other 3-wire lambda sensor mentioned above.
If that doesn’t work, the ECU might be faulty.
Where are you from — the US or Europe?