lambda sensor

[smiffy1972]

I've got a megasquirt v3 set up on my 2.0l zetec,do i need to fit a lambda sensor into the exhaust ?, i've got an ashley manifold with no hole in it

[andrewr]

You don't need to, unless you want to tune it yourself or run closed loop.

[Graham]

as above

but if you want to fit one, lambda probes use an m18 thread, so just go down your local engineering supply company/ tractors spares shop or whatever and buy an m18 nut and weld it to your manifold after drilling a hole for the probe

[smiffy1972]

So i can just tie the plug out of the way then ?

[Graham]

:thumb::thumb:

[smiffy1972]

Thanks graham :thumb::thumb::thumb:

[smiffy1972]

Also do i need to fit a fast idle valve,been talking to an ex ford mechanic and he said that they used to disconnect them on xr2i/3i's

[Zetec_Escorts]

If you are keeping the Ford inlet then use all the stuff thats on it (ISCV etc)

[smiffy1972]

Sorry forgot to mention it's got gsxr t/b's fitted to it

[andrewr]

You don't have to but it will idle much better if you do. Cold mornings will suck!!

[Graham]

Cold mornings will suck!!

why???

the ecu should ignore the lambda probe until the engine has warmed up, they only work in closed loop on a hot engine otherwise you wouldnt have any cold running enrichment

[smiffy1972]

It's only going to be a good weather car

[Miniliteman]

Sorry forgot to mention it's got gsxr t/b's fitted to it

A fast idle valve is only to be used on a single butterfly (throttle) system.

[smiffy1972]

A fast idle valve is only to be used on a single butterfly (throttle) system.

So i can't fit one anyway then

[traven16v]

I am also building a 2.0 Zetec runnng Megasquirt. What Lambda sensor should I be using? I've seen 2, 3, and 4 wire universal Lambda sensors. I know the 2 (usually white) wires are heater wires.

Or should go for a wide band setup?

Cheers.

[Graham]

if you want to use it for mapping purposes you need a wideband

[wildo105e]

If you go wide band you will also need a controller have a look at Innovate lc 1 (i think) you can buy these with the lambda sensor which is usually a bosch one. This plugs straight in the controller then the controller has one wire to the MS and then a live and earth and a callibration wire. This does add a fair exspense on the MS setup but gives you far more accuracy if you wish to tune the engine yourself:thumb:.

[traven16v]

So I wont be able to map my ecu at all without a wideband lambda sensor?

[DarthVader]

I always thought closed-loop control automapped the ECU .

[wildo105e]

Yes you can map it without a narrowband or wideband sensor but you will have no idea what changes you make actually do except for visual signs black smoke or pinking etc. The sensors tell you exactly
Both narrow and wide sensors give you a figure of how the mixture is. You aim to get stoichemetric of about 13.8 (i think) with a wideband under load. If it is higher or lower you adjust accordingly. there are utilities to data log this and adjust for you or with later ms i understand you can run closed loop which does this on the fly i.e constantly remapping to get it perfect under all conditions.

Anyone add in if i have this all wrong :thumb:

[Tinde]

Narrowband is not very accurate, it just tells you if you are on the rich or lean side of the stoichiometric fuel ratio (14.7 with gasoline). Wide band gives the actual fuel ratio (10-20AFR).

Megasquirt has closed loop lambda control. Both, narrow and wide band can be used. Actually, it has also map for the target AFR values so you can use lambda correction for cruising (lean) and full throttle (rich) and between.

I have LC-1 in both my Megasquirted cars and I've mapped them myself using the datalogging/tuning program (MegaLogViewer). Both are running closed loop also.

I wouldn't try to map anything without at least narrow band, not even carbs.

[andrewr]

" Cold mornings will suck!!"
why???

the ecu should ignore the lambda probe until the engine has warmed up, they only work in closed loop on a hot engine otherwise you wouldnt have any cold running enrichment
Bit of a delayed reply.. I was refering to without a idle air vale, not an oxygen sensor (was asked after the O2 question!). In my experience its really hard to get a car to idle cold without extra air.

[neilm]

Apologies for the blatant Pimp...

BUT

We do a Lambda boss with a bung plug £10 delivered.

[Graham]

Bit of a delayed reply.. I was refering to without a idle air vale, not an oxygen sensor (was asked after the O2 question!). In my experience its really hard to get a car to idle cold without extra air

not so, my cars dont run an idle valve but will idle when cold, its all done with ignition timing,

with the engine upto temperature you adjust the throttle stops to keep the engine idling at the "target speed" you want with the ignition timing a couple of degrees retarded over what give the fastest natural idle, if the idle drops below the target speed the ecu map simply adds a couple of degrees of adavance and he engine will speed up.

to help keep the engine alive when cold you just add a little more timing via a temp correction map

[Graham]

Apologies for the blatant Pimp...

BUT

We do a Lambda boss with a bung plug £10 delivered.



very nice neil, says i as im about to weld a nut to my exhaust and fill the vacant hole with a 20 year old pinto spark plug :thinking:

[neilm]

Ah.. the 101 uses for an old spark plug.... we used to used them as weights for fishing when I was a lad... during the war...