(T) acceleration dead spots

"Starts fine, idles fine, revs up from standing fine, just dies when pulling away. Yes, it's the same from cold and warm"

"This week I have noticed acceleration problems in that from cold it is like driving an old wreck - jumping and no acceleration"

I was thinking the lambda could be ruled out if it does the same when cold as the lambda is ignored until the engine is warm enough

The lambda is not ignored when cold, its readings are not seen by the ecu as particularly relevant so given a low priority, but on phase 4 engines the ecu monitors lambda from about thirty seconds after startup. Dont forget the top lambda sensor monitors emissions and this is then stored after switch off to be used for the next engine run (self adaptive), so if the info is duff thats been stored previously the ecu will start to mess up the cold start. If you have examiner or a multumeter you can monitor the lambda sensor reading, ideally the reading should be a waveform oscillating from 100 mv to 900 mv, switching quickly (at three thousand revs when engine hot) you should get 12 minimum and maximum readings. Typically with a slow lambda the readings will be less frequent and reduced voltage oscillations typically staying must tighter to its base reading of 450 mv. If I get time I will scan a waveform taken from a Stilo 1.6 with a dodgy lambda and post it for you guys to take a look.

That's interesting. I may plug in the laptop and see when the Stilo goes into closed loop later. I know my Bravo takes around 5 mins even with a lambda heater as you can feel it. I thought the Stilo was quicker but not as quick as 30 secs, that's a surprise. Cheers for the info

Anyway, back to Megsdad, how are you getting on? If you need to get a top lambda then it will probably be an order job from the dealers

Hey you guys, I can't thank you all enough. Lambda sensor it is!! Just taken it for a trip around the block and runs (probably) better than ever. Will try and get a new sensor tomorrow. Does anyone know how far it can be driven without the sensor connected or is that just too much to ask....!?

If anyone needs a Lamda theres one on Ebay ATM for a 1.6

Hi everyone, just a quick Q,

Where abots is the Lambda sensor located on an abarth engine.


Thanks in advance

Megsdad "Does anyone know how far it can be driven without the sensor connected or is that just too much to ask....!?"
If you have disconnected the top lambda sensor then it the ECU will go to base settings and will be quite driveable, not great but not terrible either, certainly ok to go to pick up parts etc. There are probably thousands of vehicles going around at the moment with duff sensors, many not even realising it

Kk1 Where abouts is the Lambda sensor located on an abarth engine?
I think you have quite a few lambda sensors on the Abarth, upper left, upper right and one for each cat

My 1.6 Stilo has always suffered from uneven running and no one has ever found the fault. I've changed coils, plugs and even the map sensor but no change. I'd like to try this, and can see the connector for the top lambda sensor. My question is: if I unplug it I'd expect an error light, but if I then plug the sensor back in, will it automatically start using it again, and will the error light eventually disappear after so many starts, or would I need to go to a dealer to sort it? I'm out of ideas otherwise, but the running quality of my Stilo can and often does differ every trip, but is constant for the length of the trip. I'm wondering if this could tie in with NumanR mentioning it storing parameters for the next trip at turn off.
Thanks,
Derek

"My question is: if I unplug it I'd expect an error light"
yes probably

but if I then plug the sensor back in, will it automatically start using it again"
Yes, that's what happens when you put a new one in

and will the error light eventually disappear after so many starts"
Yes

Could I ask where the connector is for the bottom Lambda sensor on a 1.6 ? I can see the top one, and am considering disconnecting them both to see if I get a consistent run from the car instead of a different quality every time I start the car. From what I have read in this and the other post about silicon on lambda sensors, it will be OK to run the car for a short while without both connected? I can put up with a below par ride for a while to test, as long as it isn't quietly killing the engine.

Thanks.