Alfa Romeo Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
143 Posts
Discussion Starter #1
Well I got stuck into my car this weekend and got a few things done. I'm now down to just one flashy ARC light!

I also fitted a heated O2 sensor from an Audi 5 cylinder. Ran 12V to heat it from the fuel pump relay (just like the factory cars). Is there any polarity on a heated O2 sensor? I'd guess not since it is just a resistor going to ground.

I ran a shielded wire to the ECU and wired the sensor wire and shield in per the wiring diagram. I put the jumper in as per Craig's page.

All done I went for a drive. First impressions?

Yuck!! Absolutley horrible. Huge flat spots between 2000 and 4000 rpm. Drivable but doesn't have the free revving nature of a normal TS. Foot to the floor it seems fine, just that part throttle feel that just doesn't seem good.

Pulled the jumper to check I hadn't ****ed anything up with the ECU out and it went back to normal.

My bar LED O2 sensor readout I normally use is duff so I'll get that repaired and make sure the sensor is responding as it should.
 

·
Registered
Joined
·
6 Posts
Hi,

just to clarify, the Lambda signal is pin24 on Motronic, and you need to pull pin27 GND to get Lambda ON.

The Heater is OK as you have it, polatiry does not matter. After engine ON after approx. 30s - 1min depending on the Lambda probe temperature you should have on pin24 the signal changing between 150..250mV to 850mV.

May you have a little bit slow lambda sensor, because of it is already overused, and this is why you have at part throttle incorrect signal - the Lambda sensor can not follow the changes happening in the exhaust line and hestiate.

Check the signal on pin 24. You should not have problems at part throttle with a fully functional Lambda sensor. I just installed mine like you did, and the part throttle response is better.

kizzo
 

·
Registered
Joined
·
237 Posts
Richard what version of the Motronic are you running on your TS? I have a non cat version computer if you can buy if you want to get rid of your O2 sensor.

Pegards
Phil.
 

·
Registered
Joined
·
237 Posts
Thanks Craig. I didn't think there was another version, but then again I've never seen a TS with an O2 senser. I have 4 TS's at home.. (all in different states) and non of them have cats. I just presumed the computer would have to be different to handle it.

If Richard is having difficultly with his, wouldn't it be easier to remove the sensor (or replace with a resister to fool the ECU) and re-tune the AFM to suit.

Cheers
Phil.
 

·
Registered
Joined
·
143 Posts
Discussion Starter #7
... and because I can! :D

NZ new (and I assume Aussie) TS models never came with O2 sensors as back in the day we only had leaded fuel, which kills them in no time.

The ECU is identical on all models (I have a spare also, but thanks for the offer), the only difference being the addition of a catalytic converter, the O2 sensor and a different fuel quality plug.

The addition of an O2 sensor should yield slightly better fuel economy in cruise and at idle. The idle richness screw on the airflow meter is inhibited when you use an O2 sensor and I figured it was cheaper to use an O2 sensor that put the car on a gas analyser just to twiddle with that.

I have a plug-in O2 sensor display which is kaput. Once repaired it will show whether the sensor is responding correctly. Easier to read than a multimeter. The sensor I got was used, so I'll get another and see how that works.

Also with the O2 sensor I could run 91 octane! It would just be worth running a tank to see how it goes! I suspect it will be way too gutless due to the retardation keeping it away from the knock point.

Richard
 
1 - 7 of 7 Posts
Top