Citrojim's Pixo, Saxo and Cycling Tales

[Hell Razor5543]

I spent Christmas Lunch with my Mum, who is currently moored in Reading, and then Christmas evening with my God Family. I will see Mum again today. Her Christmas cake is a highlight of the season.

[CitroJim]

Excellent James Do enjoy!

Her Christmas cake is a highlight of the season.

Mine turned out brilliantly this year. Baked in early October and left to mature... And it's dairy-free too

[Hell Razor5543]

Mums' were part of a batch from last year. Boy, have they matured well!!!

[CitroJim]

Just returned from a near-1000 calorie burn in the shape of a 10 mile trail (cross-country) run with my Running Club, the Redway Runners...

https://connect.garmin.com/modern/activity/2397172036#

That's nicely seen off the excesses of yesterday

This is my first proper trail run as previously I've always run on the road/pavement/tarmac and only ventured off-road in the bone dry, never in boggy mud

Almost a half-marathon too I need to do a lot more of these as I have found a new running love

There's something magical about running out in the countryside and even the mud is great! Also, there's a lot less stress and impact on your joints and feet so with that and the lovely natural scenery and clean air it's a win all the way

A fantastic start to Boxing Day

I now need to get myself a proper pair of trail shoes... Wish I'd known before... I could have asked Santa for some...

[Zelandeth]

Just pondering ideas...

I don't know how much data is out there about the ECU used in the Saxo. For the Lada there's data out there down to exactly what values are in each memory cell in the map (think it's in the EFi manual actually). If that info is out there, wonder if it would be possible to read out the data from the EPROM and verify it (is it socketed?). Next question would be whether it's rewritable. Wonder if not whether there's any possibility of an aftermarket chip that could be used? Seem to recall that sort of thing was quite common in the car magazines back in the day. Possibly easier to find than a replacement ECU with a known keypad code!

Just spitballing ideas really!

[CitroJim]

Just pondering ideas...

They're good Zel and well worth looking into... I know the ELIT won't but there may be other ways... Needs a bit of research...

We must speak in depth and look into what can be done...

[xantia_v6]

The main fuelling and timing maps (with parameters of RPM and MAP/MAF) will be held in read-only memory, and is very unlikely to have been corrupted (it will be checksummed and throw a fault if corrupted).

On top of the values from the main map, various corrections (e.g. for temperature) are applied from coarser maps with much fewer mapping points, these are also in read-only memory.

On top of these are correction maps of learned settings from feedback from the oxygen sensor and knock sensor. These may be held in EEROM, but are more likely just in RAM but don't have many data points, in order that the learning process is quick and stable. It is only this last set of maps that is really vulnerable to memory failure.

I think that there are 2 symptoms to be pondered here:
Firstly, what is pushing the ECU into open-loop mode (so that it is not correcting the lean mixture),
Secondly, why is the open-loop mixture lean?

Either of these conditions could exist on their own without causing the stumble, but it is both happening simultaneously that is causing the problem. Both conditions may or may not be triggered by the same hardware failure.

[Pug_XUD_KeenAmateur]

I've entered a MK to Amsterdam and back bike ride today

do try to visit the Ij Brouwerij while in Amsterdam, its delightfully quirky, and if you favour a strong Belgian style brew, the Beer is just superb.... nearly as nice as the location in a converted Public Loo beside De Gooyer Windmill! They keep surprisingly short opening hours, so check they're open before setting out.

Close to Camping Zeeburg, also highly recommended.

We favour the Harwich-Hook route rather than Dover-Calais, beautiful boats too.

NB: vintage electronics, still using a 1990's (possibly 80's) Sony HST-D501 Midi daily.

[xantia_v6]

What fuel are you putting into the Saxo? Modern blends (with ethanol) do burn leaner in open loop mode.
This (if it is a problem) can be compensated for by trimming the coolant temperature sensor with an external resistor.

[CitroJim]

do try to visit the Ij Brouwerij while in Amsterdam, its delightfully quirky, and if you favour a strong Belgian style brew, the Beer is just superb.... nearly as nice as the location in a converted Public Loo beside De Gooyer Windmill! They keep surprisingly short opening hours, so check they're open before setting out.

Now that sounds amazing... I don't drink sadly - due to medical reasons - but it does not stop me enjoying quirky little things like that Handy having a pub in a loo too

I think that there are 2 symptoms to be pondered here:
Firstly, what is pushing the ECU into open-loop mode (so that it is not correcting the lean mixture),
Secondly, why is the open-loop mixture lean?

Either of these conditions could exist on their own without causing the stumble, but it is both happening simultaneously that is causing the problem. Both conditions may or may not be triggered by the same hardware failure.

Absolutely spot-on Mike but why only from half-hot and not from a stone-cold start when the problem never appears? That's what confuses and baffles me...

What fuel are you putting into the Saxo? Modern blends (with ethanol) do burn leaner in open loop mode.
This (if it is a problem) can be compensated for by trimming the coolant temperature sensor with an external resistor.

Normal unleaded stuff... Normally Esso or BP - quality stuff and never cheap supermarket stuff...

When, in the very fullness of the time - around February on current usage - I'll tank it up on premium and see if anything changes... Or even perhaps chuck a bottle of octane booster in...

[xantia_v6]

Don't waste the octane booster, it is the oxygen (ethanol) content of the fuel that matters.

It would still be worth checking out the TPS.

[CitroJim]

Noted on the octane booster...

It would still be worth checking out the TPS.

Yes, as this is the thing that throws the fault... I shall shortly be putting up another wanted ad for one attached to a complete throttle body...

[Zelandeth]

Be worth looking at the resistance of the TPS and see if it's changing smoothly. AVO probably best for this rather than a digital meter.

Just seems odd that the TPS fault only shows up under these specific conditions... I'd expect it to be glitchy or not...not glitchy, but only-when-it-feels-like-it.

It's a really odd one...

[CitroJim]

Just seems odd that the TPS fault only shows up under these specific conditions... I'd expect it to be glitchy or not...not glitchy, but only-when-it-feels-like-it.

Yes, exactly... I just can't get my head around it

[CitroJim]

It's been a tremendously lovely day today and too good not to enjoy a long bike ride after parkrun and then do a bit to the cars...

I've readied the 207 for its new owner... All now ready for collection...

I ran up the Skoda to warm it through and keep the battery in good nick... It started on the button after priming it

And I've swapped the fuel pump back to the original on the Saxo now I know it was not the cause of the problem... I had two reasons for swapping it back... The unbelievably cheap pattern one I bought via eBay works OK but it is very noisy (in not a particularly nice way) and the fuel gauge sender is very inaccurate...

It's OK as a spare but if the original does pack up I'd now possibly strip out just the pump and keep the original gauge sender...

Just in case it is the cause of the problem, and I doubt very much that it is, I swapped the double injection relay... I can't see how it is but it's the last thing I've not swapped apart from the ECU or throttle body...

And to round off the day I had a lovely visit from an old friend I've not seen in ages

It's been a good day