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lambda sensor
piddy - 17/12/06 at 06:30 PM

I believe that my lambda sensor is faulty.
It was second hand when I fitted it on to the car.
when running the engine viewing it through mega tune the AFR gauge some times shows and seems to work but most of the time just shows maximum.
My question is should I buy another narrow band one or is it worth buying a wideband one?

[Edited on 17/12/06 by piddy]

chriscook - 17/12/06 at 07:07 PM

A narrow band sensor only works around the correct AFR. It basically only says if the AFR is 14.7, higher or lower. If you are going to tune on the road then it should make life a lot easier if you get a wide band lambda and controller.

(I've not got this far with my MS install yet so I may be talking rubbish but i think i'm right.)

mark chandler - 17/12/06 at 07:22 PM

When I have played around with mixtures and lambda senors I have always found them creeping into the rich zone and staying there !

If you boot it the sensor will be very rich, on the overun lean, beyond that without closed loop operation its all a bit hit and miss IMHO as weak is scray so richen it up...

piddy - 17/12/06 at 08:44 PM

Ok thanks chaps.
Probaly not a faulty Lambda then.

CairB - 17/12/06 at 09:18 PM

I have found the LCI wideband O2 system to be very useful.
Your a bit in the dark where it matters (around full bore) without wb IMHO.

Cheers,

Colin

ZetecVan - 19/12/06 at 09:49 PM

My lambda was second hand, and that 'became' faulty after a couple of months. I got a brand new one (NB) and tuned it (megasquirt/megalog viewer). It ran fine, but was down on power. I got a WB and re-tuned it and it feels like a different car (van!).

If you can afford it, get a WB. Mines an LC-1

Steve Lovelock - 28/12/06 at 01:22 PM

I want to get a wide band sensor second hand, any idea what cars I should look at in the scrap yard as a suitable donor?

martyn_16v - 28/12/06 at 08:40 PM

quote:
Originally posted by Steve Lovelock
I want to get a wide band sensor second hand, any idea what cars I should look at in the scrap yard as a suitable donor?


mk4 golf? The sensor on it's own isn't much use though, widebands need a controller to drive the pump cell and correctly read it, this will be built in to the OEM ECU on production cars. Personally I wouldn't bother with a scrapyard sensor, they're fairly fragile things and I wouldn't trust it to work right (or at all). Compared to the cost of the controller the sensor itself isn't much, I got my last one from Techedge in Aus for about 30 quid (ordered it with the 2A0 controller). They'll be just as cheap if not more if you order one with a controller from the US at the current exchange rate

Steve Lovelock - 29/12/06 at 07:31 AM

do I need a controller when running megasquirt?

martyn_16v - 29/12/06 at 10:04 PM

yup

Steve Lovelock - 30/12/06 at 02:27 PM

This feels like it is too much of an expense and hassle. Am I going to lose much by not using a lambda sensor with my MSnSE?

paulf - 30/12/06 at 02:43 PM

I am using a secondhand narrow band sensor that cost me £5 for 3 from the scrapyard,I didnt want to pay for a wideband as im having to use leaded fuel due to the crossflow requiring it and was concerned about damaging the sensor.
I tested the sensors using a blowlamp and volt meter and found them all to work ok and fitted one to my car, it has allowed me to tune to a good usable MAP using dataloging and real time tuning with the laptop.
I did manage to get the car running without the sensor but there is no real way apart from engine response and feel to tell if it is anywhere near correct, at least with the narrow band i can make sure it is running rich at full throttle and about the correct ratio when cruising and low throttle .
Paul.

quote:
Originally posted by Steve Lovelock
This feels like it is too much of an expense and hassle. Am I going to lose much by not using a lambda sensor with my MSnSE?

TangoMan - 30/12/06 at 02:45 PM

The expense is not that bad!!!! You may lose lots by not having one as you will struggle to get it set up properly without.
As for hassle, an LC1 is really easy to wire in and it will save loads of hassle when tuning.

Well that's what I think so I have an LC1 going in with my MS install. Phil who wrote the MSNS coding (or part of it) uses an LC1 and recommends them.

martyn_16v - 30/12/06 at 03:09 PM

If you're not too sick of soldering by the time you've finished the MS have a look at the Techedge 2A0 or 2E0 DIY kits. Both work out well under £150 complete with sensor etc and work perfectly fine, i've been using my 2A0 for a couple of years now.

Whether it's worth buying one or not depends on how you see yourself tuning it. If you're likely to want to fiddle with it constantly and do as much tuning yourself as you can then I can't recommend it enough, but if you're more likely to take it to a rolling road, get it set up and then leave it be it's not really worth the expense.

MikeRJ - 30/12/06 at 03:54 PM

quote:
Originally posted by Steve Lovelock
This feels like it is too much of an expense and hassle. Am I going to lose much by not using a lambda sensor with my MSnSE?


If you are not going to have it mapped on a rolling road, then anything you manage to acheive with a narrow band sensor will be a compromise, you won't know how rich or weak the engine is running at any given point, just that it is running rich or weak.

Caution dictates you err on the rich side at WOT for safety, but you don't have to go very far rich to start losing power (and of course economy).

Steve Lovelock - 30/12/06 at 05:42 PM

Do narrow band sensors need a controller?

If not then what type of car has them?

£150 is too much for me for a wide band and a controller. Also, once I have the MSnSE running and set up using the self tuning software (hopefully) I don't really want to be playing with it on a regular basis. I'm using a Vx Redtop so hope to get 170+ BHP and am not really fussed about maxing out the power available. So if a narrow band sensor works reasonably well and I can get them from a breakers yard for £5 then great, I'll take it.

martyn_16v - 30/12/06 at 07:19 PM

quote:
Originally posted by Steve Lovelock
Also, once I have the MSnSE running and set up using the self tuning software (hopefully)


Autotune only works with a wideband. If you do want a narowband from a scrappy just look for anything mid-90's with a catalytic converter, they'll all have one.

EDIT: Oh, and a narrowband sensor doesn't need any controllers, the ECU can read it directly

[Edited on 30/12/06 by martyn_16v]

martyn_16v - 30/12/06 at 07:22 PM

Just had another late thought, Bill Shurvinton hires out LC1 widebands at reasonable prices...

paulf - 30/12/06 at 07:34 PM

I tuned mine manually with the narrowband and then used the new version of Megalog viewer with the ve tuning function , it will work with narrow band or wide band but obviously is better with the wideband set up.
If the car is going to be rolling roaded then just fit a narrowband to allow it to fine tune itself after rolling road tuning.
The one I used came from a Rover 800 but most newer cars have suitable ones , go for a 4 wire one to allow it to warm up quicker and work at low throttle openings.
New narrow bands are only about £30 from a motorfactor or Ebay, but I used ones from the breakers as I didnt know how they would last with leaded fuel .
Paul.

quote:
Originally posted by martyn_16v
Autotune only works with a wideband. If you do want a narowband from a scrappy just look for anything mid-90's with a catalytic converter, they'll all have one.

EDIT: Oh, and a narrowband sensor doesn't need any controllers, the ECU can read it directly

[Edited on 30/12/06 by martyn_16v]