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[TheBoy]

...so did something change between the oxford calibration and the miss daisy calibration? Or was it just drifting out of tune because of the weather? The guy I was talking too re prins kit mentioned that fitting 8mill fuel pipe helps in cold weather, but I think we all already have that... Don't we?

My point was, the other calibrations were done by ragging the tits off it, and I could count the total lags on the fingers of one hand.

Calibrated at Miss Daisy speeds, the thing can't do a redline 1st to 2nd change without the engine falling out the bottom of the car.


The last calibration was done in 2 journeys over about 80 miles, the green line was moving all the time, depending on if it was a motorway cruise, going through Oxford, or the roundabouts around the A43.


The O2 integrators were flying around (as they do on pre DBW engines), but were in right ballpark for the condition, and idle and partial load o2 settings were constant-ish (pre DBW don't have the short/long term trim readings)

Yep, understood the differance in calibration conditions, see where your coming from... but what made you re calibrate again for miss Daisy in the first place? Thinking about it, Iirc, did I read something changed after/during certification? Or something like?

Emmissions fubar, and o2 BLMs hard pinned at one end of scale...

[Kevin Wood]

IMHO, all issues of multivalve size, pipe size, cold weather, vapouriser, etc. can be eliminated by looking at the vapour pressure in the LPG tuning software. It will drop by perhaps 10% at full throttle but to cause a running issue would have to be worse than that IMHO.

Kevin

[Lazydocker]

Right, it's not a pressure issue, we've ruled that out already as Kevin says. I still think it can be tuned out, although I still haven't managed it on mine I just drive around the issue.

Chris, when we calibrated yours at the Essex meet I thought we had it pretty good :-/ I know there was still a little bit of lag but felt it was pretty close to being right. It was certainly better than I've ever managed to get mine!

TB, interesting that since calibrating with a more "normal" driving style has brought the lag into play. Perhaps the answer is to calibrate it driving with plenty of enthusiasm  :-/

What I do know is that the Stag kit is still the best option IMO! It's considerably cheaper than most of the competitors offerings and it is, essentially, just a combination of parts from well known manufacturers

As for Teilo... I (personally) would still use him but would chase him hard until I have all my stuff sorted! As Tunnie has seen, I can get hold of him and get results pretty quickly for most things, although I am struggling to get in and see him to try and get the lag looked at that said, I know a lot of people had difficulty getting hold of him and I don't feel I can recommend him as I used to  If anyone wants to use him I'm more than happy to give them his details. You do get a kit that contains everything you need at a very good price

[Kevin Wood]

My take on the calibration issue :-

The problem occurs at wide open throttle. During this phase of operation the engine is operating open-loop so, during calibration, you are not getting any feedback from the vehicle's ECU by way of changing injector times.

The automatic calibration extrapolates the idle fuelling to cover the wide-open-throttle part of the map but all that can really be done in this region is to check that the engine is not going lean.

I wonder if it's time to hook up a wideband lambda sensor to a car and actually tune this region properly?

The other aspect is that if a large fuel trim has built up, you will be chasing your tail, so, if possible, reset it, or at least run it on petrol for a while before calibrating.

The fact that calibration has made a difference (albeit in the wrong direction) in this case does give me some hope, actually.

Kevin