Technical MPI lambda sensor

[ronnieronson]

Anyone know off hand what the part number is for the front (pre-cat) lambda is, or where I can get one cheap?

Also anyone know of lambdas from other engines which might be suitable?

Cheers

 

[Smiler121]

I saved quite a few quid swapping both Lambdas (changed one & it turned out to be the other that was dead) by buying cheaply listed Alpha Romeo Lambdas for about £15 then cutting the wire & re-fitting the plastic plug from my existing Lambda.

Many Lambdas share the same sensor but they use longer leads & all have plugs with a plastic notch sticking out in different places, which stops them from fitting over your connector. As long as you wire the proper Cento plug on correctly (only 4 wires) you'll be fine.

www.ngk.co.uk gives a selector that also helps explain things & to know which OEM sensor you want.

Take a look at http://cgi.ebay.co.uk/Lambda-O2-Sen...photoQQcmdZViewItemQQ_trksidZp1742.m153.l1262 (Ebay item 370062893446) sold by airflowmeter, gives a few suggestions.

 

[randomizered]

I've got a pre cat in my bag of bits you can have for P+P (not a for sale thread )

It was working when it was removed.

I also have the post car, but the wired have been cut on that one.

You get that compression test done?

Kristian

 

[ronnieronson]

I saved quite a few quid swapping both Lambdas (changed one & it turned out to be the other that was dead) by buying cheaply listed Alpha Romeo Lambdas for about £15 then cutting the wire & re-fitting the plastic plug from my existing Lambda.

Many Lambdas share the same sensor but they use longer leads & all have plugs with a plastic notch sticking out in different places, which stops them from fitting over your connector. As long as you wire the proper Cento plug on correctly (only 4 wires) you'll be fine.

www.ngk.co.uk gives a selector that also helps explain things & to know which OEM sensor you want.

Take a look at http://cgi.ebay.co.uk/Lambda-O2-Sen...photoQQcmdZViewItemQQ_trksidZp1742.m153.l1262 (Ebay item 370062893446) sold by airflowmeter, gives a few suggestions.

That's a great find mate - thanks
Thinking I might get a pair of universal ones - they come with heat shrink, and can't possibly be any worse than my faulty ones

Got quoted by Andrew Page for £72 ex vat!!! for a genuine one, and begrudge paying so much

 

[ronnieronson]

I've got a pre cat in my bag of bits you can have for P+P (not a for sale thread )

It was working when it was removed.

I also have the post car, but the wired have been cut on that one.

You get that compression test done?

Kristian

perfect!
you are a legend!
- PM on it's way!

not got the compression test done yet, but have bought a tester - not got a day off for another 5 days, but will try and get that sorted asap.
Ran the car with pre-cat lambda unplugged, and absolutely nothing changed!, so I can only assume that it's fubar!
Unplugged the post cat lambda, and that made the ecu spaz out - so pretty sure that one's ok for now

 

[ycming]

Those universal one .. is utter rubbish ... used them before no good .

In my experienece they last around 1 year .. sometime less

Ming

 

[Smiler121]

I've got a pre cat in my bag of bits you can have for P+P (not a for sale thread )

It was working when it was removed.

I also have the post car, but the wired have been cut on that one.

You get that compression test done?

Kristian

I'd have Kristian's post cat off him too if I were you & re-use the plug off your knackered one on that.

ycming - I've read that the Universal ones aren't great quality myself.

 

[J.R Racing]

Yes I personally think you are better sticking with OE ones. Even if they are second hand.

I briefly had an aftermarket one off a friend brand new who gave it to me for nothing and it started losing fuelling response after around 6 months.

I then ordered two new OE ones and has been perfect since and fuelling well.

 

[ronnieronson]

Well, thanks to the legend that is Kristian - a mysterious parcel turned up for me today... containing Lambda sensors! Woooo!

Was an absolute total cock of a job it was!
Foolishly I had my 1st attempt almost immediately after driving home from work - and I am now the unfortunate wearer of some weird little burns on my right wrist, from trying to get my hand behind the heat shield.

an hour later I took the bolts off the heat shield, and manouvered it down enough to get a 7/8ths spanner in there and undo the nut (which came off suprisingly easily!).
New lambda went in, tightened everything back up & last but not least - reset the ecu.

Test drive results:
Car still idles a little roughly - but now it's equally cold or hot.
Fan doesn't seem to cut in quite as much - which is nice.
Idle rpm is no longer erratic or on the verge of stalling - at a guess i'd say 800-850 rpm - cold or hot.

I'm guessing there is still something at fault somewhere - so it's back to the list (cheifly replace the coils and do a compression test), but at least she feels safer to drive again

I cannot express just how thankful I am to FiatForum - but specifically Kristian - absolute Legend!

 

[Most Easterly Pandas]

The only other Fiat that the Sei shares it's Lambda with is the Panda. From what I remember when looking for part number for my Panda, it listed it as being compatable for both

Jon.

 

[AppleSei]

The only other Fiat that the Sei shares it's Lambda with is the Panda.

i am assuming that is only for SPI sei though and not MPI which is needed here, in which case the panda one will be useless??

 

[Smiler121]

I'd like to know (but I'm not bothered enough to look it up) if there is actually any difference in the sensor used in the Mpi vs Spi - when you take a look an the link I posted earlier it really does appear that a large amount of sensors are the same but the lead length & connector type are different.

 

[ronnieronson]

well after a bit of rewiring, and lots of oil on the old nut, I managed to get the post cat one swapped.
Fuel economy seems better (though i wont know until ive done a full tanks worth of driving)- and the idle is holding quite well at approx 800 rpm.
Next job of course is to do a compression test, and double check all my hoses... But that said im much much happier with the way she runs

 

[ronnieronson]

Well, a week on, and shes done nearly 190 miles on 3/4 of a tank, which has consisted of 95% "spirited" town driving.

Compared to the previous 180 miles per tank I'm well happy - starting to see the kind of fuel economy I came to love from Bertie.... damn I miss that car...

Idle is still a little iffy - feels like a missfire every 10 seconds or so.
To make sure its not igintion related, I've administered another new set of leads, plugs and a fresh set of coils - but this seems to have helped very little.

Still to do a compression test (I know - should have done this with the coils and plugs out, but sorta forgot and was pushed for time this morning), and I'm still none the wiser about what hoses to check, and infact how to check them

 

[Smiler121]

Can anyone confirm which of the 2 plugs the pre-cat sensor on an Mpi Sei is supposed to go into?

 

[cc1]

Can anyone confirm which of the 2 plugs the pre-cat sensor on an Mpi Sei is supposed to go into?

Looks like;
Red
White
Yellow/Black
White/Brown

 

[Smiler121]

Sorry but I'm actually looking to know physically which plug socket does the lambda plug into, I'm trying to confirm that they haven't mixed them up.

At the moment the two yellow boxes highlight the 2 ends of the pre-cat lambda?

 

[randomizered]

cc1 has listed the wire colors. Each will have different colours, trace them back a bit up the loom, and one of them should have the colours listed.

I seem to rmember they only really fit the one way round though?

Kristian

 

[Smiler121]

I still don't think I'm getting the answer I need.

I am happy with the wiring of the sensors themselves but I need to know which socket the sensor I highlighted plugs into - does it plug into the socket I highlighted or the socket that isn't show in the picture?

Or do you mean that those are the colours of the plug that the pre-cat sensor goes into?

 

[cc1]

Or do you mean that those are the colours of the plug that the pre-cat sensor goes into?

Yes.
The engine harness has different cable colours to identify which plug is pre/post cat sensor as the lambda sensor cables are the same colour.