Air/Fuel gauge

slindborg

you will see (if its resolution is fast enough) the A/FR dancing round your "centre value" as the ECU controller is whats known as a "Bang Bang" setup where it will run richer than its calibrated settings till the feedback from the lambda shows its rich, then run leaner than calibrated till the sensor says its lean, ad infinium.

Yello

vocky said:
well mine seems to stay around 14.5, my Lc1 is before the cat.

Isn`t that a little lean at high revs? dunno..

vocky

slindborg said:
you will see (if its resolution is fast enough) the A/FR dancing round your "centre value" as the ECU controller is whats known as a "Bang Bang" setup where it will run richer than its calibrated settings till the feedback from the lambda shows its rich, then run leaner than calibrated till the sensor says its lean, ad infinium.

that is what happens, it constantly changes and adjusts

Yello said:

vocky said:
well mine seems to stay around 14.5, my Lc1 is before the cat.

Isn`t that a little lean at high revs? dunno..

I've not really monitored it enough yet, especially at higher revs, but certainly at cruise conditions it sits around 14 - 14.5

Yello

Mine is around 14.6-14.7 in closed loop, in open loop from appr. 3500rpm it`s around 13.2 but leans of at top because of the injectors. 30lbs injectors have arrived 😃

vocky

I'm waiting for some better weather for some long drives 8)

I need to monitor the fuel pressure, a/f readings and some other stuff :roll:

Steve_Crisp

The Mixture Lambda as two white heater-wires as you know. Putting 12v across the two wires on an old lambda I've got makes it warm up quite nicely as you'd expect.

I then measured the voltage that the lambda gets from the VX wiring loom at the harness connector - the wires to the lambda-connector come directly from the big ECU plugs.

Onewhite is definately 12 volts as expected. The other wite is not an earth though. If I measure across the whites at the connector with no load (ie no lambda) then it measures around 6 volts. If I measure the non-12v white wire to ground then I get nothing. It leads me to suspect that the lambda gets a 12v feed from the ECU via one white wire, but the other white wire doesn't go ground, but is somehow controlled by the ECU - for what purpose I have no idea, because I believe that removing the 12v across a lambda when the engine is running is detrimental?

It doesn't stop me carrying on with fitting the Innovate but I don't like mysteries! I will probably use the 12v white to power a relay (as per Vocky's suggestion), but not use the mystery white-wire on the other side of the relay - I'll just use a proper ground, and not use this mystery wire. I hope the ECU is ok with that! 😃

Regards,

Steve

vocky

this is how the O2sim is wired, so gives an idea of what the wires do dunno..

Steve_Crisp

That's the lambda simulator thingy isn't it.

It shows a load-resistor to keep the ECU happy - so I guess on that score that the ECU will not be happy if the load is not there. Do you have details on that load-resistor Vocky?

I've seen that a lambda take around 0.7 A at 12 volts, which would be 12 divided by 0.7 = roughly 18 ohms at around 8 watts?

Steve

vocky

it is around that figure, I will try and find the size used dunno..

ok found this on the 02sim site

20 Ohm, 20 W

Steve_Crisp

Magic! I'll get one...

Thanks, thumbup

Steve

rabidh

Or Maplin do 10 Watt resistors. You could get 2x 47 ohm ones - it'd cost you a grand total of 80p!

http://www.maplin.co.uk/Module.aspx?Tab ... 1&doy=13m4

Steve_Crisp

Yes, I was thinking I'd look to see what Maplins do! I want one that'll fit inside my new mounting-box inside the boot.

I've bought a 4" x 3" x 1" metal box from Maplins to house the new relay, the switch and LED from the Innovate stuff, and junctions for all the wiring. It mounts on the chassis where the VX disable-switch is in the boot, and the disable-switch then mounts onto the new box.

The first thing is to see what the new relay will draw and then add a resistor in parallel to suit.

Steve

Steve_Crisp

Hi Vocky,

Your advise please!

I've now fitted the Innovate as the primary Lambda,

The engine ran ok when I took it for a five-mile run, and it ticks over ok, but the air/fuel gauge swings from either reading "0" when driving at 60 mph, to full-scale when slowing down, and swings around wildly between the two extremes on tickover. Oh, and the cooling-fan runs all the time, but no engine-waring lights of any kind.

What a f*ck up - beginning to regret starting this! noth.

I thinking of going back to the standard lambda tomorrow if I can't work out whats going on.

Steve

vocky

it sounds like the outputs are the wrong scale, you can programme them via a laptop

Steve_Crisp

Why would the fan be running though Vocky? Is that something to do with the ECU sensing a fault of some sort?

It doesn't take long to revert to a standard primary lambda so I'd better do that first to make sure the fan stops running.
I can then try the computer program to look at the scaling of the two outputs when I've got some more time. Did you have to adjust yours when you fitted it?

Anyway, if the primary lambda was a long way out then I'd expect an engine warning light to come on or something.

I'm beginning to realise that I just don't have enough time spare in my life to play with my toys anymore!

Regards,

Steve

markv

Default the first output of the lc1 should be programmed to mimic a narrow band sensor and the second output should be full range, 0-5V.

It is however smart to put the unit on a laptop and verify. Also, check the firmware version of your lc1. Mine was shipped with a very old one. I upgraded it with the laptop, was very straight forward.

This fan is quite strange? Would be interesting to see what happens with the original sensor. If it is mounted and the fan goes of it is obviously something the ECU is doing. But would expect a light on? Or maybe it is a pending code..

Cheers,

Mark

Steve_Crisp

Hi Mark,

I put the laptop on, and it showed an AFR of around 13, but slowly dropped to around 7.4 as it warmed up on tick-over. I blipped the throttle a few times and it settled around 13. The gauge mimicked what the laptop said, so it's not that.

I decided to revert to the original setup...

I totally disconnected the LC-1 and refitted the old lamba. The engine still runs ok as far as I can tell with no lights on, but the fan still runs whilst the engine is actually running (not with just ignition on).

Trouble is, my mother's ill and I need the car working.

I guess I need to Tech2 it, but I don't have one. Do I buy one or get Vauxhall to check it out? dunno..

Regards,

Steve

vocky

pull fuse 8 (vx220) to reset the ecu

by default certain errors switch the engine fan on :roll:

markv

Rereading a part of the thread I would be interested to know how you hooked up the lc1 and if there are any changes you still have active in wiring with the original lambda back in place.

The plan on using the heater wires from the original lambda sensor to power the lc1 is a bad idea. This is the supply the ECU gives to the lambda sensor to heat up. It is not always on. The ECU determines if the lambda sensor needs to be heated. It will do this after a (cold) start, but also when the engine is idling for a while. Exhaust gasses are not warm enough the keep the lamda sensor on high enough temperature. Powering the LC1 with these wires would result in the LC1 turning off and on. If I remember the manual correctly, you should never run with the LC1 off and the engine running, risking damage to the wideband sensor.

Using a load resistor on the heating wires is a good plan. I also have one in place. Should be enough just to connect both heating wires to the resitor. ECU will think all is ok.

Had a quick browse through some error codes, but couldn't find a specific one that turn on the fan but doesn't show a check engine light.

Mark

Steve_Crisp

Thanks for the detailed replies cheers..

Well, the main point is that it's now ok again. I rang up Gurneys of Newbury who said they'd Tech2 it for me, but by the time I got there the fan had turned off and everything was as before. dunno..

Point taken on not powering the LC-1 using the heater-wires. I had put a load-resistor across the feeds from the ECU that feed the "two whites" for the lambda heater. The wire from these heater-feeds that was +12v I used to energise a relay to give me switched +12v to the LC-1. I believe that this +12v feed stays constant Mark, and it's the "earth" feed-wire that controls whether the heater is on or not? That's why when I measured across these two wires when the car was ignition-on/engine-off I didn't get 12 volts across them - just +12v on one wire when measured to chassis, and something like 5v on the other one.

Either way, I'm now going to move the relay under the dash, and power the LC-1 from there!

Secondly, I am now going to remove my exhaust primary section and weld the additional bung in-place and use the LC-1 as "info only". I'll arrange it so that I can switch the ECU between both the "old" sensor and the LC-1 when I've gained confidence.

Thanks both for your help. I'll remember the "fuse 8" thing for the next time Vocky!

Steve

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