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Yeah I don't know - I use the auto start and stop logging in csv format and auto sending to email method - I grab the raw data then and use Access or Excel to make nice pretty graphs.

Its often just too much to generate decent comparative graphs from a horde of raw data
 

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Discussion Starter #43
Ah OK...thanks for that. I feel a bit better now. I can see how to record the data in .csv format, so will give that a go.
 

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Discussion Starter #44
Upstream O2 voltage graphs - starting from ice cold engine before engine start till about 3 minutes after start - idling only don't touch the throttle.
Here's the data from the start to steady state coolant temperature. There are quite a few other parameters in there too. It's very warm today here in London - the ambient was 34C around the car. By the way, the site here wouldn't allow me to attach the .csv directly - hence the link.

Later today I'll get the LTFT figures - it was reading 4.69% on idle though.

Link to csv file
 

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LTFT at idle is in the csv already.

Did you recently reset the mixture adaptations or removed the battery?

This graph is the STFT values - ideally they should be oscillating around 0 once the LTFT has been adapted properly ...................... good news is it would seem the STFT is at least heading towards 0 avg - so I am going to guess the ECU is in control of the mixture (ito of commanding changes anyway)

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The way negative initial values makes me wonder why if you have not recently reset the adaptations.

FWIW - in Torque you can kill all the garbage parameters so they don't form part of the logging process and wont get inserted in the csv - any unnecessary info logged like gps coordinates is useless and consuming logging accuracy

Not sure why .................... that upstaream O2 voltage - on original sensors they are supposed to stick around .5V with ignition on and engine not running - wonder why its way over 1.2V
 

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Discussion Starter #46
Thanks for this. The battery hasn't been disconnected in 300 miles [since I did the rebuild]. I fitted a new one at that point. The only thing I did recently was to clear the P0130 fault code. Torque wouldn't have done something in addition to clearing fault codes ?
 

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Shouldn't have no..................... strange then (leaking fuel injector/s? ....................... fuel delivery/pressure? - did you do a fuel pressure test)

Important stuff to now monitor is LTFT and STFT behavior during a trip of constant engine speeds and road load - starting from before engine is running
 

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Discussion Starter #48
Later this afternoon we're going to take the car for a drive and log from the get go, I'll post the file up here to see how we get on. I've switched off the GPS logging as well so there'll be less superfluous data in the file. Thanks so much for all your help.
 

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FWIW:

LTFT - slow to change at a specific engine speed - want it to be close to 0 at any engine speed when in closed loop.

STFT - quick to change (in sympathy with O2 voltage upstream) - should be swinging around 0 if all is well at any fixed engine speed and road load
 

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Discussion Starter #50
Shouldn't have no..................... strange then (leaking fuel injector/s? ....................... fuel delivery/pressure? - did you do a fuel pressure test)
So sorry, I missed the first bit of your point here. You know it feels like fuel starvation when it hits that dead spot on hard acceleration.

A digression here - years ago I used to race two stroke karts. If the crankshaft oil seals were worn, the crankcase pressure would build as the revs increased. The seals would be unable to hold it and the fuel/air mixture would be compressed out through them rather than making its way to the combustion chamber. In other words, the engine would be starved of fuel/air. It would momentarily die until the revs dropped and pick up again as the pressure lowered in the crankcase. From a driving perspective, this feels exactly the same. Under hard acceleration, the engine revs rise, then the engine flattens, I lift off and can get it to go again.
 

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No problem with possible fuel starvation at high demands that's why I said fuel pressure problem possibly.

Leaking fuel injector could initially (at idle) cause way rich non-demanded instantaneous mixture so STFT will drop way way negative like here that's why I asked about fuel pressure behavior at idle and just after engine switch off

These cases my first action normally slap a cheap oil pressure gauge on the fuel rail and monitor behavior - see if normal (if fuel filter is in good condition anyway) - running engine needs around 2.5-3 Bar - after engine stop rail must stay at around 3 Bar for many minutes
 

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Discussion Starter #52
It is very very lumpy at idle, not smooth at all. I'm not sure if that's apparent from the data or not.

I'll see if I can get hold of something to measure the fuel pressure. I hope that it's not fuel filter related. The fuel filter on the Clio 182 is internal to the fuel tank and has a service interval of 150,000 miles apparently. In other words, it's not replaceable (!)
 

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Lumpiness is not evident but would not surprise me at all - 300km driven is more than enough to get the ECU to learn the mechanicals and to tune the adaptations.

No way STFT can go nuts like that and not cause LTFT to adapt ..................... to me the wild STFT with constant LTFT is an indication there is no consistency in what the ECU perceives it needs to do .................. STFT swings around 0 should be around 20 positive and negative - if its not the ECU should be fixing the LTFT to achieve the STFT swings

There is more than one LTFT figure in the ECU and its throttle input related - the fact that your ECU never ever reports it recognizing the need to use anouither is indicating the ECU doesnt know what to do and is just plodding along ......................... and that points to a a funky upstream O2. I would start there
 

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Discussion Starter #55
Thanks so much for this.

Yikes... if I replace that, it'll be the fourth new O2 sensor the car's had in less than a 1,000 miles (!) AFIK, the upstream one was a brand new, genuine Renault [Bosch] too. Anyway, looks like the parts canon needs to be loaded and fired again :)

Does the LTFT not depend on the downstream sensor at all ? That didn't appear to be registering a value on the second set of data logs [driving under load], although it did register a constant 0.41 during the start from cold process.
 

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The downstream O2 will only start feeding usable info if the upstream O2 is consistent - which it currently isnt. Also - the downstream O2 has a minimal effect on LTFT - its basically only compensating for the small drifts that can and do occur in the upstream O2's output characteristic and to confirm the cat is still there and active.

Not sure why .................... that upstream O2 voltage - on original sensors they are supposed to stick around .5V with ignition on and engine not running - wonder why its way over 1.2V
The number of O2s you replaced is unfortunate but that suspicion of mine can easily be proven to be correct since you have 2 identical sensors on the vehicle currently - ignition on and engine not running, cold.................... should be seeing around .45V on both, and not the 1.2 you reported earlier.

As for exactly what to expect on the downstream O2 - check back on what I said and graphs I posted earlier - very specific driving conditions needs to be met and maintained if you want to see it producing meaningful results.

O2s getting murdered is often a result of contamination in the engine somewhere ................. bad gasket and sealing fitment practices - especially with some silicons, gaga fuel and oil additives, raw unburnt fuel getting to the sensor etc etc
 

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Discussion Starter #57
First off I can't thank you enough for everything here.

In terms of the sensors, upstream and downstream are new but not identical. One is genuine Renault [Bosch], the other is Denso. I can't remember which is which right now, but I'll get under the car this afternoon. I may buy two brand new Denso sensors and replace both so I know I'm starting from a clear position.

When you talk about sensor contamination - is there any way I can visually inspect the sensor to see the damage [I imagine not] ? If it is the case that the car is destroying sensors, I absolutely have to figure out what's causing it. I don't put additives in my fuel. I just use standard pump unleaded. Should I use the higher octane expensive stuff ? I'm not even sure that a secondary inline fuel filter would eliminate the type of crud in the fuel that wouldn't be consumed during combustion.
I had the induction system to bits [inlet manifold off etc... during the rebuild. Everything looked fine. There was no silicone used anywhere in the reassembly. I replaced the inlet manifold gaskets as a precaution with new genuine Renault parts.

By the way, the car had it's MOT a few weeks ago and passed the emissions test. I've enclosed the emissions reading at the time as an FYI.

... OK, I'll check out the sensors today.
... Do you think it's still worth looking at the fuel pressure on the rail per your earlier suggestion ?

MOT emissions report
 

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Before you do anything first see what the O2 voltages are with engine not running - that will give you confirmation

Well - something is making O2 sensors go t1tsup .............. either bad quality sensors or some issue on the vehicle.

I can help you find a finger to point at the O2 sensor and then its going to be up to you to figure the rest - if the O2s were of good quality (and brand name stamped/printed on a thing doesn't mean its good quality imo - its too easily faked nowadays)................ there is absolutely no way the 4 should have lasted only 1000kms

I would absolutely do the fuel pressure thing yes.............. too many uncertainties here

Sensor contamination is often a chemical thing poisoning the active material on the sensor and thereby changing the sensors response characteristic ............... depending on the chemical it could be burnt off given enough time but I normally don't trust O2s in that state even if they do recover eventually..................... often not able to visually see anything

MOT pass just say that at the time of testing it was ok - nothing more
 

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Discussion Starter #59
Before you do anything first see what the O2 voltages are with engine not running - that will give you confirmation
I went out there this morning. With the ignition on and engine not running, the upstream O2 sensor voltage is 1.275v and the downstream O2 sensor voltage is 0.41v.

The upstream sensor is the Genuine Renault sensor, actually manufactured by Bosch. The downstream one is the Denso sensor.
 

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Well - as you earlier reported already - the O2s are supposed to be the same so those readings are simply not on ...................... upstream being funky imo - you really do need around midscale or 0.4V when no exhaust flow so the downstream looks ok ito that measurement atm
 
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