Rek
Well-Known Member
Has anyone added these after doing the engine swap? Both of the above send signals through to the Control Unit and seem to affect the way the car drives.
M30B35 Motronic Engine Swap - O2 sensor and Fuel Tank Breather Valve
- Thread starter Rek
- Start date
the O2 sensor is really important!
Understatement.
x_atlas0
Well-Known Member
Adding the O2 is almost trivial if you are using the stock M1.3 wiring harness. Add a bung on the downpipes and clip the sensor into the harness. Per Paul and Don, yeah, the O2 is super important to making it run correctly. Otherwise the car will default to pig rich all the time and probably pull timing, because it has no feedback on combustion effectiveness. (so it defaults to 'safe as possible')
The 'fuel tank breather valve' or PCV is more an emissions control device. In the original implementation, it opens up the intake manifold vac to a charcoal canister hooked into the fuel tank. It sucks the evaporating gasoline vapor from the tank and lets the engine use it.
The 'fuel tank breather valve' or PCV is more an emissions control device. In the original implementation, it opens up the intake manifold vac to a charcoal canister hooked into the fuel tank. It sucks the evaporating gasoline vapor from the tank and lets the engine use it.
Default on 179 ecu with disconnected O2 sensor is autogenerated .45 reference volts.
Its the lazy or worn out O2 connected sensor that “kills the cats”
Its the lazy or worn out O2 connected sensor that “kills the cats”
Rek
Well-Known Member
I fitted both. The o2 sensor improved the performance and idle considerably. For the Fuel Breather valve, I used a diode across the terminals on the plug and it had minimal effect if any.