BRC vapouriser adjusment

[Austin Shackles]

Got a BRC AT90E on the current V8 3.5 disco, running open loop. It's just
been for MOT and failed on LPG due to about 7%CO.

Having spent about 2 hours getting my CO meter to work, I concur, it's way
high at idle. Petrol CO figures look about right.

Running at 3000 rpm on LPG it was a bit high too, so turned it down to about
1% which should be OK, I reckon, but it's still showing about 7% at idle.

Now, on an OMVL I'd now be tweaking the idle settings, but I can't find them
on the BRC, if there are any. There's a small-ish brass knurled knob with a
hex on it on one side, but undoing it makes no difference to the CO so I
don't think that's it. There's also a larger knurled knob at the bottom,
which is in a place that leads me to believe it's a drain plug.

So happens I have got an OMVL which I could put on it instead, since I know
how to adjust those, but I'd prefer to know how the BRC works. Any ideas?

[Peter]

Post by Austin Shackles
Got a BRC AT90E on the current V8 3.5 disco, running open loop. It's just
been for MOT and failed on LPG due to about 7%CO.
Having spent about 2 hours getting my CO meter to work, I concur, it's way
high at idle. Petrol CO figures look about right.
Running at 3000 rptm on LPG it was a bit high too, so turned it down to about
1% which should be OK, I reckon, but it's still showing about 7% at idle.
Now, on an OMVL I'd now be tweaking the idle settings, but I can't find them
on the BRC, if there are any. There's a small-ish brass knurled knob with a
hex on it on one side, but undoing it makes no difference to the CO so I
don't think that's it. There's also a larger knurled knob at the bottom,
which is in a place that leads me to believe it's a drain plug.
So happens I have got an OMVL which I could put on it instead, since I know
how to adjust those, but I'd prefer to know how the BRC works. Any ideas?

My AT90E has got two hex thingies on the side (look closely, it's easy
to miss the other hex!), plus that small brass knob. One of the hex-es
is useless, the other does the job - screwing it in leans the mixture,
and vice versa. Small brass knob is only for fine-tuning. Big brass knob
on the bottom is drain plug, you got that right.

Hope this helps,
Peter

[Austin Shackles]

Post by Peter

Post by Austin Shackles
Got a BRC AT90E on the current V8 3.5 disco, running open loop. It's just
been for MOT and failed on LPG due to about 7%CO.
Having spent about 2 hours getting my CO meter to work, I concur, it's way
high at idle. Petrol CO figures look about right.
Running at 3000 rptm on LPG it was a bit high too, so turned it down to about
1% which should be OK, I reckon, but it's still showing about 7% at idle.
Now, on an OMVL I'd now be tweaking the idle settings, but I can't find them
on the BRC, if there are any. There's a small-ish brass knurled knob with a
hex on it on one side, but undoing it makes no difference to the CO so I
don't think that's it. There's also a larger knurled knob at the bottom,
which is in a place that leads me to believe it's a drain plug.
So happens I have got an OMVL which I could put on it instead, since I know
how to adjust those, but I'd prefer to know how the BRC works. Any ideas?

My AT90E has got two hex thingies on the side (look closely, it's easy
to miss the other hex!), plus that small brass knob. One of the hex-es
is useless, the other does the job - screwing it in leans the mixture,
and vice versa. Small brass knob is only for fine-tuning. Big brass knob
on the bottom is drain plug, you got that right.

Hmmm. no sign of other hexes, but then it's not in the ideal place for
looking at it. I'll have another look next time it's both light and not
raining (much). The small brass knob doesn't appear to do anything to the
mixture.

On the OMVL, one adjuster is fixed bleed and the other is mixture, dunno if
the BRC is similar. The fixed bleed is only really there I think so that it
doesn't stall from inertia when going from high-vacuum (e.g. over-run)
straight to idle.

[Tom Woods]

On Thu, 22 Feb 2007 19:08:45 +0000, Austin Shackles

Post by Austin Shackles

Post by Peter
My AT90E has got two hex thingies on the side (look closely, it's easy
to miss the other hex!), plus that small brass knob. One of the hex-es
is useless, the other does the job - screwing it in leans the mixture,
and vice versa. Small brass knob is only for fine-tuning. Big brass knob
on the bottom is drain plug, you got that right.

Hmmm. no sign of other hexes, but then it's not in the ideal place for
looking at it. I'll have another look next time it's both light and not
raining (much). The small brass knob doesn't appear to do anything to the
mixture.
On the OMVL, one adjuster is fixed bleed and the other is mixture, dunno if
the BRC is similar. The fixed bleed is only really there I think so that it
doesn't stall from inertia when going from high-vacuum (e.g. over-run)
straight to idle.

Its like alt.fan.lpg here tonight :)

Have you not got a friendly local converter you can ring up austin?

[Yvan]

Nedavno Austin Shackles pise:

| Having spent about 2 hours getting my CO meter to work, I concur,
| it's way high at idle. Petrol CO figures look about right.


Sorry, can't help you with your problem but I wanted to ask you
something. I am considering getting one (used) CO meter of eBay. Is
it maintenance free, or do I need filters to change? Does it need
calibration, and how do you do that? Anything else?

[Tom Woods]

Post by Yvan
| Having spent about 2 hours getting my CO meter to work, I concur,
| it's way high at idle. Petrol CO figures look about right.
Sorry, can't help you with your problem but I wanted to ask you
something. I am considering getting one (used) CO meter of eBay. Is
it maintenance free, or do I need filters to change? Does it need
calibration, and how do you do that? Anything else?

I have a gunsons one (came from ebay). It is maintenance free.

You calibrate it by leaving it outside for as long as possible (min
15mins to get a good calibration in my experience), then adjusting it
so that it reads 2%.

Im not sure id buy one again. I have a wideband 02 sensor and
controller in my car now and i think putting the money towards a
wideband sensor and controller would be more use (it will probably
cost you £150-£200 and you can get an adaptor to hold the sensor
itself in the tailpipe.

[Yvan]

Nedavno Tom Woods pise:

| I have a gunsons one (came from ebay). It is maintenance free.
|
| You calibrate it by leaving it outside for as long as possible (min
| 15mins to get a good calibration in my experience), then adjusting it
| so that it reads 2%.
|
| Im not sure id buy one again. I have a wideband 02 sensor and
| controller in my car now and i think putting the money towards a
| wideband sensor and controller would be more use (it will probably
| cost you £150-£200 and you can get an adaptor to hold the sensor
| itself in the tailpipe.

You can buy Bosch wideband sensor for £70 here:

http://www.lambdasensor.com/main/mwide.htm

What does controller do? I just finished my air - fuel meter that I
found it here:

http://www.pelicanparts.com/techarticles/mult_air_fuel_monitor/mult_air_fuel_monitor.htm

It's a simple 0-1V voltmeter. I guess that one you have does a lot more.

Can you explain how do you use it, it's benefits...

[Tom Woods]

Post by Yvan
| I have a gunsons one (came from ebay). It is maintenance free.
|
| You calibrate it by leaving it outside for as long as possible (min
| 15mins to get a good calibration in my experience), then adjusting it
| so that it reads 2%.
|
| Im not sure id buy one again. I have a wideband 02 sensor and
| controller in my car now and i think putting the money towards a
| wideband sensor and controller would be more use (it will probably
| cost you £150-£200 and you can get an adaptor to hold the sensor
| itself in the tailpipe.
http://www.lambdasensor.com/main/mwide.htm
What does controller do? I just finished my air - fuel meter that I
http://www.pelicanparts.com/techarticles/mult_air_fuel_monitor/mult_air_fuel_monitor.htm
It's a simple 0-1V voltmeter. I guess that one you have does a lot more.

I bought one of these:
http://www.innovatemotorsports.com/products/lc1.php

I think that the controller sorts out the heating element in the
lambda sensor itself (so only runs it as required) and also lets me
datalog it straight onto a PC (which also gives me a nice readout of
the CO/lambda on the screen).
It says in the blurb that it does some calibration stuff too but im
not sure what if any.

Post by Yvan
Can you explain how do you use it, it's benefits...

My wideband is fixed into my downpipe. I currently use it while
driving to datalog the air/fuel. (i also drive a simple LED gauge off
it)

No benefits over doing it how you have i dont think.

You can buy (or make) a clamp to hold the lamda probe in the exhaust
and you could then easily use it to tune multiple cars.

[Austin Shackles]

Post by Yvan
| Having spent about 2 hours getting my CO meter to work, I concur,
| it's way high at idle. Petrol CO figures look about right.
Sorry, can't help you with your problem but I wanted to ask you
something. I am considering getting one (used) CO meter of eBay. Is
it maintenance free, or do I need filters to change? Does it need
calibration, and how do you do that? Anything else?

The gunsons elcheapo ones are not worth it IMHO, I had one and gave up on
it.

Mine's a very old one called "Sun" which is rather a work of art. It seems
to work, though, which is a good thing as I've no idea how to fix it.

[Yvan]

Nedavno Austin Shackles piše:

| >| Having spent about 2 hours getting my CO meter to work, I concur,
| >| it's way high at idle. Petrol CO figures look about right.

|
| The gunsons elcheapo ones are not worth it IMHO, I had one and gave
| up on it.
|
| Mine's a very old one called "Sun" which is rather a work of art. It
| seems to work, though, which is a good thing as I've no idea how to
| fix it.

I was thinking of old Sun or Bosch unit. You say nothing about filters,
calibration maintenance. What did you do for two hours getting it to
work?

[Austin Shackles]

Post by Yvan
| >| Having spent about 2 hours getting my CO meter to work, I concur,
| >| it's way high at idle. Petrol CO figures look about right.
|
| The gunsons elcheapo ones are not worth it IMHO, I had one and gave
| up on it.
|
| Mine's a very old one called "Sun" which is rather a work of art. It
| seems to work, though, which is a good thing as I've no idea how to
| fix it.
I was thinking of old Sun or Bosch unit. You say nothing about filters,
calibration maintenance. What did you do for two hours getting it to
work?

mainly, find out how it works. Initially, I decided that the pump wasn't
pumping. Having pulled it apart a bit, I decided that it was a blocked jet.
Having looked at it more, I found that it doesn't actually suck on the inlet
pipe: the exhaust blows thorough the system, and the pump sucks some of it
out of the pipe as it goes past. Having realised that, I then modified the
end of the pipe into the exhaust so as to make more exhaust flow through the
machine, and then it worked.

It should be said that I've not got the original pipe from the exhaust -
it's possible that it should be bigger bore.

[mark]

Post by Yvan
| Having spent about 2 hours getting my CO meter to work, I concur,
| it's way high at idle. Petrol CO figures look about right.
Sorry, can't help you with your problem but I wanted to ask you
something. I am considering getting one (used) CO meter of eBay. Is
it maintenance free, or do I need filters to change? Does it need
calibration, and how do you do that? Anything else?
--
___ ____
/__/ / \ ** Registrovani korisnik Linuksa #291606 **
/ / \/ /\ \ ** Registered Linux user #291606 **
/__/\____/--\__\ **http://counter.li.org/**

I have this one ...it's OK ..cost me a £5er from car boot sale ...guy
thought it was a battery charger.

actually this is a snap-on one ...just the other name they trade
under ..

Loading Image...

works great ...the only trouble is ...that the resolution is two
digits ....
so its 0.0 to 9.9 ...not great as these days cars are putting out CO
in the 0.000 range.

still i get to test my car before the mot and see that it is less than
0.2 for petrol ......and 3.5 LPG

handy for seeing faults ...

in the pic ...its showing 0.00....this is running on petrol...lpg was
the same. actually after on the proper mot machine it was showing 0.07
on petrol ...like i said last digit is there for show ....its always 0


the two perspex chambers you see are meant to have filters in
them ...available from snap-on at ....guess what.....£38 for
100 ....hence they ain't in play ..


calibration is done with the probe out of the exhaust and it sucking
in fresh air ....then you just zero it ....

cant see the point of sending it to snap-on and having it properly
calibrated ...as its just not accurate enough anyways in the
resolution department ...


BTW ...when ever i tried to tune my old mixer system with this i ended
up with flat spots ...

the best way to use these ...is this way ...


to get your car to run as best as you can ...by acceleration
runs ...etc ...


then plug this in and note and write down the readings .....so when
you next tune ...you can just get it running and tuned ...by using it
and setting up with your old figures ...so avoids tearing up and down
the road ...annoying neighbours.

BBBTW, one with a greater resolution is going to cost a lot ...
even these sell on ebay for £80 plus second hand.


All the best.mark