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Adaptations SHOULD reset upon battery removal long enough yes (there is also Renault speaking scanners/software that can accomplish the same without battery disconnection) ............... be aware though that most other adaptations will also get lost - the faff with the lights in my recipe is there to ensure your throttle body gets adapted in a organized fashion BEFORE you start the engine else you end up with funky or impossible idling behavior

O2 heater is always on as long as ignition is on - forced and by design - thats the reason for the basic question of what is the O2 reading - there is no feedback mechanism to manage the O2 temperature (not on this particular control system anyway)
 

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Discussion Starter #82
This will be the crux of the matter ................... is that now better/improved? - I cannot get a feel for it in the logs but it would seem its either gone or way better
Much improved... no dead spot and I could feel the dephaser kick in a 5,000 rpm as it ran all the way to the top.

I'll clear the fault code today and run the car as is for the remainder of the week [hopefully it stays away]. I expect the new sensors will probably be here on Friday, whereupon I'll reset the fuel adaptations and do some more logging next week.
 

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Discussion Starter #83
So a development yesterday. This time I was driving the car for slightly longer than my usual 10-15 minutes from cold... all in an urban environment - so stop-start-traffic etc... After around 30 minutes or so while the car was stopped in traffic, and the engine idling, the check engine light began flashing. It continued to flash for several minutes even when I was moving off and then it went out. I had to visit somebody, so the car was stopped for a few hours. I then started it again to take the 20 minute [urban] drive home. This time while driving the check engine light began flashing and again kept it up for a few minutes before extinguishing. I vaguely remember seeing a flashing check engine light months ago and I'm now beginning to think this could be the smoking gun.

The car was not misfiring when the light was flashing... there was no noticeable difference in the engine idle for example... but it doesn't idle smoothly at all. Certainly when driving I couldn't feel it misfiring.

A quick online search throws up a variety of possible causes for this on the Clio 182... but the common denominator among solutions appears to be the injectors.
 

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Before you start chasing injectors (which may be a possibility yes):

First sort the O2s properly because they are a known issue at this stage............. and can be the cause of this flashing too

The fuel pressure test I mentioned earlier - if done properly and the O2s are known to perform to spec, then one can get a lot of free info on the status of the injectors from that.

Leave the scanner plugged in and have torque running all the time next time you see the flashing get a scan on the ECU and see if you pick up a pending code BEFORE THE IGNITION IS SWITCHED OFF ...................log the cylinder misfire numbers for this period of flashing spanner.

The flashing behavior thing - there is really only one way of chasing this down if you want to limit the spending of unnecessary cash - log every engine parameter for every trip you take - its free - and if you run into the flashing situation you have reference data to interpret ................. educated guesses leads to expensive school fees only
 

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Discussion Starter #85
I guess what's concerning me most is that the car is destroying O2 sensors [at almost £60 a pop]... within a hundred or so miles... so damage may be occurring outside of when the spanner is flashing. I'm actually nervous of driving the thing at all right now.

I'm wondering whether it's better at this stage to try and go down the fuel pressure test route ?
 

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Well - its up to you - I suggested the testing of fuel pressure right in the beginning.

As for "testing fuel injectors" ................ how and by who and using what method?

guess what's concerning me most is that the car is destroying O2 sensors [at almost £60 a pop]... within a hundred or so miles... so damage may be occurring outside of when the spanner is flashing. I'm actually nervous of driving the thing at all right now.
The peace of mind to achieve is the proper expected O2 voltage graphs, a very small LTFT and a STFT oscillating around 0 - once those have been proven to exist permanently on the vehicle no testing of injectors will prevent destruction of O2s
 

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Discussion Starter #87
The one thing I failed to do when I tested the fuel pressure at the weekend was to leave the gauge in place until several minutes after I'd turned the engine off. I guess I really need to do that as a matter of priority. Is there anything more I need to do here do you think ?

In terms of testing the injectors, from what I read I can't see any definitive way of verifying a fault with them. They can issue a fault code [which mine don't]. They can have a dull, rather than metallic , clicking sound [mine appear to sound OK]. The resistance across them may be incorrect [this I've not checked as my multimeter's packed up]. The only other option is to replace them... but that's using my wallet in an attempt eliminate a POSSIBLE cause without knowing for sure.

I guess I'm caught between a rock and a hard place right now.
 

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Discussion Starter #89
Anything else is a waste of time and money
You're right. I'll reconfigure Torque to capture a lot more and keep it hooked up for the next few days... see what we get. I don't have the fuel pressure test gear, so will need to wait until my friend's next available to bring that round.

As always, really appreciate all your help.
 

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Discussion Starter #90
A moment ago I had to go for a 40 minute urban drive. A bit before that I spent a some time setting up more comprehensive logging on Torque. I logged my entire journey, it's attached below. At the very end of the journey, when I got home, I had the car idle for a little while. During this time the check engine light started flashing. I immediately did a fault code scan [while it was flashing] and it registered P0301 - Cylinder 1 Misfire Detected. So potentially we're a little closer to diagnosing where the problem might be.

40 minute urban journey with extensive logging on
 

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So once again it would seem the upstream O2 is now doing the expected job properly - voltage oscillating nicely.

STFT imo is about as good as you will ever get - as I said before the swing should be around 0 and plus or minus 20 values to be acceptable.

LTFT while static, has a very small and acceptable value and with the STFT doing what it is I really wouldn't expect any major changes any time soon

Once again its the downstream O2 that suddenly wakes up after quite a long time to produce very decent values - important to note its not initially doing that though.

Interesting - the red bits I marked all occur at the same time by the looks of it on all 3 parameters and I am going to guess that is also exactly when your misfire moan occurred


So now the question is what is happening to cause the moan ................. and the parameters logged imo is not giving you the answer............... the STFT is responding in sympathy with the O2's requirement during the moan period so the ECU seems to be in control of the electronics - but is what you experience and see a cause and effect thing and which comes first? ................ also - the downstream O2's voltage during the moan doesn't make sense and contradicts the upstream O2

So its either a mechanical issue (air leak confined to that particular cylinder, plug, coil,injector etc etc) or ??????????????????

Really do need confirmation of proper pressure behavior of the fuel rail now

I would change the plug and coil on cylinder 1 and move/swap them with cylinder 4's and see if the misfire now moves to cylinder 4 if it returns - certainly spend NO money till the downstream O2 is producing reliable and believable results from the get go.

o2 DOWN.jpg
o2 UP.jpg
STFT.jpg
 

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Discussion Starter #92
First off, massive thanks for everything here... this is so helpful.

The LTFT hasn't changed at all [not even to the third decimal] since I swapped the Denso sensor upstream, so maybe the ECU is not able to use the data from the downstream sensor ? My new O2 sensors have arrived, so I'm going to change the downstream one at some stage over the weekend [assuming the weather behaves itself].

The flattening of the data at all three points will be the misfire. I'd be very interested to understand exactly what that means - neat fuel going past the sensor ? Fuel combusting across the sensor ? Whatever it is, it's possibly damaging the sensor as it does it.

Yes, moving the plug/coil pack from cylinder one is a very good idea to eliminate anything electrical. I'll do that also.

Just one point in terms of the fuel pressure test. The testing kit my friend has hooks up to the fuel line as it leaves the tank - i.e. you lift the rear seat and attach the connector there rather than onto the fuel rail under the hood.
 

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Glad you find it helpful - speaking to other mechanics you may find people going about the same problem you have using a different approach, but that's personal choice and as long as my approach brings me results then I am going to stick with it

There is no absolute NEED to have a constantly variable LTFT value - not at all - if the STFT behaves normally then all the adaptation required on the LTFT by the ECU has already happened and if there is no obvious NEED to change the fuel map it will not happen (eg - on my own K4M the fuel trim values has been stuck for the last about 8 months already). Also keep in mind that the STFT has a 20% margin to do short term corrections on fuel trim - only when STFT starts to constantly report a trend in a particular direction will the LTFT be adapted to get the STFT avg back to 0

Also - if you actually do have a constantly variable LTFT experience on every trip there is something seriously wrong - most likely the fuel quality.

The flattening of the data at all three points will be the misfire. I'd be very interested to understand exactly what that means - neat fuel going past the sensor ? Fuel combusting across the sensor ? Whatever it is, it's possibly damaging the sensor as it does it.
While the engine is idling and you don't touch the throttle, there is absolutely no expectation to see a flatlining of the O2 voltage - if you do you better figure why.

Since the engine as a whole gets reported on by a single O2 (and not an O2 per cylinder) its virtually impossible to say what is happening on a particular cylinder.

If like in your case you get lucky to have a specific cylinder ALSO getting fingered by a code then then you can think about the possibilities - so while the O2 is flatlining in a very lean area, the STFT is indicating the ECU is seeing this and chucking a lot of extra fuel in (STFT way high around 40 for extended time) ................ whether its enough to end up as raw fuel in the exhaust I don't know, but all you can do is try to sort the misfire and see if the O2 and STFT will again show a problem

Just one point in terms of the fuel pressure test. The testing kit my friend has hooks up to the fuel line as it leaves the tank - i.e. you lift the rear seat and attach the connector there rather than onto the fuel rail under the hood.
Nope - that is not rail pressure - its pump output pressure - you want to see the actual fuel rail pressure behind the injectors - there is a fuel pressure regulator on the rail that modulates the rail pressure based on intake vacuum (throttle pos) and if it goes funky it can cause all sorts of problems - more importantly the injector's ability to not leak is reflected in the rail pressure getting maintained around 2.5Bar+ for many 10s of seconds after the engine stops
 

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Discussion Starter #94
Nope - that is not rail pressure - its pump output pressure - you want to see the actual fuel rail pressure behind the injectors - there is a fuel pressure regulator on the rail that modulates the rail pressure based on intake vacuum (throttle pos) and if it goes funky it can cause all sorts of problems - more importantly the injector's ability to not leak is reflected in the rail pressure getting maintained around 2.5Bar+ for many 10s of seconds after the engine stops
Real quick reply for now before I head out the door...
I kinda suspected that would be the case. Unfortunately I'm going to have an issue capturing this reading as the kit doesn't have any adaptors to get onto the unions in/around the rail.
 

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Discussion Starter #97
Yes, moving the plug/coil pack from cylinder one is a very good idea to eliminate anything electrical. I'll do that also.
Complete brainfade... I won't be moving the coilpack from cylinder 1 to cylinder 4 [see below] :D :p I should have remembered that as I'd the whole thing to pieces in February.

I'll change the plug and HT leads and fit a new O2 sensor downstream... but the prime suspect - injector in cylinder one - is looking more and more guilty by the day.

Clio 182 coilpack
 

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Discussion Starter #98
OK bit of a mixed day... I took all the bits off to get at the HT leads and plugs on the car. I managed to swap the plug [which looked OK by the way - see below] from cylinder 1 to cylinder 2 but couldn't swap the cylinder 1 HT lead with any of the others. The HT leads are in a mini-loom and are just precisely long enough to go their own plug... cylinder 1 being the longest of course ! So I guess that's as much as I can do in terms of electrical elimination, save from buying a new set of HT leads and/or a new coil pack.

The good news is that I fitted the new Denso sensor downstream and it appears to be behaving as we expect it to be.

I cleared the P0301 fault code and then took the car for a 20 minute urban drive. When I got back home, I left the engine idling until I saw the flashing spanner light return... it took a while but it reappeared. I did a scan and it's P0301 back again. The full log is below.

File with new downstream O2 sensor
 

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Ok progress then. That new downstream O2 is doing its thing properly now by the looks of it.

ITO chasing O2s - just to repeat - always check on the voltage reported when engine is not running - more often than not it will save you a ton of time and money - any funky measurement seen here sort this first because it is a known problem and will cause other issues

O2.jpg


Still have that funky flatlining thing on the upstream O2 getting reported so I would guess the P0301 return is to be expected.

If you are unable to confirm the fuel pressure behavior on the rail I would suggest swap injectors (cyl 1 and 4) and see if the P0301 gets another name because the problem moved to another cylinder.

From the looks of that plug I'd say there is no raw fuel leaving the engine now .................. if anything it looks borderline lean (you do have cylinder 1 as near the gearbox eh?)

Time to reset adaptations now and see what gives?

I see you had it standing idling quite a while before driving off - next time log while you get in and start driving immediately - see if you can get close to the AP200 graphs I posted before for both the upstream and downstream O2s - it will tell you if the cat is still ok
 

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Discussion Starter #100
From the looks of that plug I'd say there is no raw fuel leaving the engine now .................. if anything it looks borderline lean (you do have cylinder 1 as near the gearbox eh?)

Time to reset adaptations now and see what gives?
It's possibly lean... the plug in cylinder 2 looked the same though.

I was contemplating swapping injectors... maybe I should do that first before resetting the adaptations ? What do you think ?
 
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