Chris_C wrote: or the fact I just worked out I averaged 24.5MPG on the last tank...

Want to buy a nice T4?
http://www.volvoforums.org.uk/showthread.php?t=152797

Boot it everywhere and youll still come away with that.

You're not trying hard enough Ben

Can't believe you're selling that beauty, that looks like a lovely example. I'm having to sell my T4 too - really don't want to, but house purchase requires much more mileage.

Seems like you've been driving enthusiastically judging by that tank then, Chris?

24.5mpg seems pretty good to me!

I'd be very happy if ether of my cars got that.

SteveP wrote:You're not trying hard enough Ben

Can't believe you're selling that beauty, that looks like a lovely example.

Almost in the same boat as you Im affraid. Im doing high miles, but all short journeys. Need a Dweezil or a vegmobile. (again)

All lanes work

232,000

That last 1,000 have been a pain in the backside. The last 2 weekends she's done 400 miles, including today of Southampton, Hanger Lane, Watford, drive around a bit, Watford, Winchester, Southampton. Sat in London traffic on a Saturday, she was perfectly happy, a new set of leads have made the idle much nicer (1000 +/-100 before, 900+/-50 now)

So, onto clearing up some bits from previous. Senders, giving dodgy signals. I think I have a clue what is causing this, but I'll post the evidence first.

Red, battery voltage; Purple, spark trigger from ECU into coil; Green, inductive pickup on pluglead 4
Spark can be noted at falling edge of trigger, note also the noise picked up via inductive pickup of sparks on other leads.

Note also the noise on the spark trigger and battery voltage lines, both jumping ~35V from normal. That'd upset it, even if just for such a short time frame.

So, lets look at CPS signal. Ok, we can see the missing teeth, and all the normal teeth. And in the middle, a mosh. That's not right. Wonder if that coincides with a spark

Why, yes it does... what a surprise.

Look at the drop of CPS voltage when trigger goes high. *If* the ECU used basic threshold detection, it'd see that drop as the missing teeth on the flywheel and get epically confused. Then it'd see the giant mong directly after than (dead middle of screen) and it'd think we were doing 2x or 3x actual revs.

A quick look at Max and Min on this one is quite revealing. Signal of CPS is at 1v/div (noted at top of screen) CPS ground is 2.5 squares below the main waveform, so a signal that is centered at 2.5, +/-1V. Sounds about right. Apart from when it's spiked by the spark. Then it's 5V higher than it ought be.

So, originally I thought a bad block earth creating an impedance at high frequency would give you this, effectively lifting the PD of the block for a split second. It still could well be that, but I do have another thought. The inductive pickup I first made for the plug leads was 7 turns of wire, and generated >1000V in the pickup. So I reduced this eventually to a half turn, i.e a wire crossing at 90degrees but not wrapped. That *only* picked up 400V. I have a load of my engine loom between the dizzy and the block, i.e. running across all 4 plug leads.... plonker.

I find this very interesting, you dosnt love studying waveforms?

How good quality are those plug wires of yours? Some can be very leaky, there are some specially expensive ones that claim to be more noise free...

I did use R plugs, which are supposed to reduce electrical 'noise', but don't know if those did anything to me, anyway there is sort of rule, near plug wires no wires, but with COP system one can ignore that, I guess.

Can be bit of work to reroute the loom, can you split some wires or do you have to make new loom?

Chris, I love graphs They tell a story and are so much easier to understand than guessing symptoms. Even if the story they tell is your car is running like a Ford

I've just fitted new leads Jani, it has made a difference. I had a good talk with pettaw in the pub a week or so ago about all this, as ever he had good insightful ideas about where to start (she's currently missing the odd spark too, giving a lumpy idle and as Andy said, that'll be confusing the ECU via the lambda)

Loom, well I keep moving parts around so the wires at the moment are mainly still individual. It shouldn't be to hard, but thing is I don't want to just extend wires as I like clean signals and no solder joints. So, I need to get a load of ECU pin crimps and re run each individual wire. Whilst I'm doing all that I want my MAP sensor moved, along with more wire on my IAT sender, rerun the fuel pump wire a different direction (that is controlled by the ECU on the F7's, it's a sexy self priming system) and I've found that Williams's (maybe the 16V's too, but not sure on that) should run an aux electric water pump so if the thing is still hot when you park her up that kicks in. With the autosoloing and some stagey stuff I do that'd be super useful, so I want that too. Whilst I'm there, I could move the coil pack so I don't have to run the 1.7 340 king lead, the clio one is super short, the 1.7 lead is an aerial almost the width of the engine bay. Maybe Renault did that for a reason.

I'm also tempted to co-ax a heck of a lot of the sensors, so, I'm currently just working out how to do all of this in the best way. I'm aware I have an MOT coming up, so I also need to do non engine related stuffs. So... I'm tempted to make a second loom at the moment. That way, I can do it off the car and just do a straight swap one day. I also want to move the ECU somewhere, I'm just not sure where. I don't like the inner wing like Adam normally does his looms, when the pair of us did mine we put it under the glove box. But I'm almost tempted to put it down where the GLT ECU lives, though I've a feeling I hid my bluetooth thingy down there

Chris_C wrote:Chris, I love graphs They tell a story and are so much easier to understand than guessing symptoms. Even if the story they tell is your car is running like a Ford

I've just fitted new leads Jani, it has made a difference. I had a good talk with pettaw in the pub a week or so ago about all this, as ever he had good insightful ideas about where to start (she's currently missing the odd spark too, giving a lumpy idle and as Andy said, that'll be confusing the ECU via the lambda)

Loom, well I keep moving parts around so the wires at the moment are mainly still individual. It shouldn't be to hard, but thing is I don't want to just extend wires as I like clean signals and no solder joints. So, I need to get a load of ECU pin crimps and re run each individual wire. Whilst I'm doing all that I want my MAP sensor moved, along with more wire on my IAT sender, rerun the fuel pump wire a different direction (that is controlled by the ECU on the F7's, it's a sexy self priming system) and I've found that Williams's (maybe the 16V's too, but not sure on that) should run an aux electric water pump so if the thing is still hot when you park her up that kicks in. With the autosoloing and some stagey stuff I do that'd be super useful, so I want that too. Whilst I'm there, I could move the coil pack so I don't have to run the 1.7 340 king lead, the clio one is super short, the 1.7 lead is an aerial almost the width of the engine bay. Maybe Renault did that for a reason.

I'm also tempted to co-ax a heck of a lot of the sensors, so, I'm currently just working out how to do all of this in the best way. I'm aware I have an MOT coming up, so I also need to do non engine related stuffs. So... I'm tempted to make a second loom at the moment. That way, I can do it off the car and just do a straight swap one day. I also want to move the ECU somewhere, I'm just not sure where. I don't like the inner wing like Adam normally does his looms, when the pair of us did mine we put it under the glove box. But I'm almost tempted to put it down where the GLT ECU lives, though I've a feeling I hid my bluetooth thingy down there

Hmm, I would say that you are showing symptomps of gadgeteering, even it is fairly harmless condition, it is often one that prevents one to accomplish one simple thing because there would be so many more that would be handy to do while at it

Guess why I still have 60's 70's wallpapers on my house that are becoming apart? Would be handy to install heat pump and extra insulation while at it

Anyway, it is great to know the why, it is simpler to move to how from that point

Chris_C wrote:I'm also tempted to co-ax a heck of a lot of the sensors

You can't go around wiring stuff up properly, it might work then and where would be the fun in that?

I would make sure the crank sensor is wired up properly screened but the rest probably aren't worth it if you can route the wires away from noisy things like plug leads. Momentary confusion about something like air or coolant temperature isn't going to upset anything very much.

I'd put the MAP sensor somewhere it's safe from noise like inside the car.

At my placement we used MDA and I had to go through data proccessed by matlab (as well as fix the matlab programme which seem to break at random ), find problems, then use MDA to find the dodgy car and then find the problem with the car. It was a very clear way of finding a fault, although i remmber one occasion when some people working there managed to have an opinionated discussion about a clear fault

Matlab is awesome! If you have the VR toolbox, type vr_octavia into the prompt

Zombeh, amusingly Renault screens nothing but the knock. Makes no sense to me! The IAT just needs to be longer, it's a stretch atm. MAP indoors makes some sense, that's what my turbo has as standard.

this is all fascinating gibberish.

Like watching The Open University.

In Bulgarian.

volvosneverdie wrote:this is all fascinating gibberish.

Like watching The Open University.

In Bulgarian.

Така че, какъв е проблемът?