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[Lazydocker]

Gay!  Very Gay actually! Show it who's boss.

Large manly can of Italian tune up for you....

Errm... I seem to have caught something from you

I used to drive sedately most of the time but just lately

Keeps the pre cat code away ime. :-/

But even the local LPG station has commented that I'm filling up frequently

Incidentally... That tank took 64L from empty and I got 250 miles

[Kevin Wood]

It's been a while I know...

Next time you're over this way perhaps we should swap MAF sensors and give it a try?

Kevin

[JamesV6CDX]

Yes please!

Just when I thought it was OK, I booted it to overtake a campervan on a 2 lane sliproad this weekend. Admittedly I had 4 people in the car, and a boot full of stuff, but still it really did feel like a 2.0!!!

I'm not sure if it's just me, but it seems to run WORSE on super unleaded / higher octane fuels  :-/

[aaronjb]

I'm not sure if it's just me, but it seems to run WORSE on super unleaded / higher octane fuels  :-/

Hmm.. knock sensor causing full retard permanently? I think that could conceivably show a drop in power with super (as it's harder to ignite and takes more ignition advance happily)..

Though ISTR from past discussions that we've already covered the knock sensor?

[JamesV6CDX]

Though ISTR from past discussions that we've already covered the knock sensor?

I'm not sure about that.

Admittedly, "My Naff Code Reader" results for knock were similar between myself and Jimbob,

But -

On the Tech2, No manner of driving could get the knock-control active to show on Kevin Wood's 3.2, whereas on mine - the lightest throttle will make it show...

[aaronjb]

Though ISTR from past discussions that we've already covered the knock sensor?

I'm not sure about that.

Admittedly, "My Naff Code Reader" results for knock were similar between myself and Jimbob,

But -

On the Tech2, No manner of driving could get the knock-control active to show on Kevin Wood's 3.2, whereas on mine - the lightest throttle will make it show...

Ah yes - now I remember.. I think - though I'll bow to superior knowledge on this - that ignition retard would show a 'greater' effect the higher the octane rating of the fuel?

It did seem hinkey that you could get knock control active on yours but not Kevin's. Wonder if the MaxiScan MS509 shows knock control? If it does I'll have a look at mine.

[Marks DTM Calib]

The higher the octane rating, the more ignition ADVANCE that can be accomodated.

If the knock system detects a fault its simply retards the ignition to a set position and disables the active control.

If this happens, then its VERY down on power

[aaronjb]

The higher the octane rating, the more ignition ADVANCE that can be accomodated.

I think I said that somewhere up there.. but doesn't the flame front also propagate more slowly with a higher octane fuel?

[Kevin Wood]

The higher the octane rating, the more ignition ADVANCE that can be accomodated.

I think I said that somewhere up there.. but doesn't the flame front also propagate more slowly with a higher octane fuel?

I don't believe so, or at least not significantly so. The main difference is that it is stable against detonation at higher combinations of temperature and pressure. Once it's burning I doubt there's much difference.

I really can't see a reason why it would be more sluggish on high octane fuel, except that, depending where you buy it and how much they turn over, it is often in worse condition than the 95 RON. Been there myself.

Kevin

[aaronjb]

I don't believe so, or at least not significantly so. The main difference is that it is stable against detonation at higher combinations of temperature and pressure. Once it's burning I doubt there's much difference.

Ah - then I'll go back to sleep now

it is often in worse condition than the 95 RON. Been there myself.

I've seen that effect too - monitoring knock vs. ignition advance on the MR2 I couldn't get any more advance into the system (without knock) on Optimax from a low-traffic petrol station than I could with super unleaded from a high-traffic petrol station.. (Mapped it on Super in the end)

[Kevin Wood]

I wonder if it's got one or more cylinders running lean? Either a knackered MAF (although there was nothing to suggest this in the live data that james posted IIRC) or a clogged injector?

As I recall knock retard was going active according to the Tech 2 at anything above "cruising" levels of throttle and, as said, I couldn't provoke that on my car at all. :-/

[JamesV6CDX]

Can I just add that, disconnecting both knock sensors, doesn't make any difference at all to the performance. It doesn't get better, or worse...

[JamesV6CDX]

I wonder if it's got one or more cylinders running lean?

I think I posted somewhere on this thread Kev - I don't think it's right that I get over 34mpg on a 70mph run..  :-/

[aaronjb]

I wonder if it's got one or more cylinders running lean?

I think I posted somewhere on this thread Kev - I don't think it's right that I get over 34mpg on a 70mph run..  :-/

It's possible but unlikely - I got 28-29mpg on an 85mph run, you could save quite a bit of fuel at 70.. maybe.

[Kevin Wood]

I wonder if it's got one or more cylinders running lean?

I think I posted somewhere on this thread Kev - I don't think it's right that I get over 34mpg on a 70mph run..  :-/

It's possible but unlikely - I got 28-29mpg on an 85mph run, you could save quite a bit of fuel at 70.. maybe.

That sounds Ok if it was 70MPH all the time. Running lean won't necessarily improve fuel consumption either.

Hmm. Thinking about it, I reckon at times when it goes into knock retard the load is light enough to still be closed loop, so fuel trims would have taken care of it. :-/