MOT failure on emission test

[Kirstin]

Hi there,

I need help! We rebuilt our Elise MK2 with k Rover engine and now she has failed the MOT so many times I have stopped counting. We brought her to Murray in Edinburgh, but instead of fixing our emission they simply found some new MOT issues (despite the emission). They recommended to replace the catalyst which we did with actually no difference.

Her new parts are:

new pistons

head cylinder new

new catalyst

lambda sensor before rebuilt last year renewed

new spark plugs

new rotor and ignition cab

all filters new

She fails on fast idle (2000 revs) at 0.8 % instead of the required 0.3%. All other measurements are ok, including HC

Has anyone come across a similar issue or does anyone have any suggestions?

Maybe, the sensors?

Spring is there and the green frog is not roadworthy :-(

Many thanks in advance to everybody!

Kirstin

[Jonathan]

My 106 GTi did this last year.

I ONLY just got it under by ragging the arse off of it to get it absolutly red hot for the test and even then it took about 30mins at fast idle to get it to pass (top bloke at Nationwide Autocentres bent every rule in the book, what can I say....)

It was like at 0.40 - 0.39 - 0.37 creeeping down until it finally went under - never seen the temp gauge so high !

When I sold the car it was burning a fair bit of oil and possibly underheating - I never got to test it but I think the temp sensor was reading slightly under value and also possibly the O2 sensor had contamination with the burning oil stopping it from reading the right values.

I would clean the O2 sensor, check the engine temperature and scale, replace the plug leads if they are old.

Check for any bad seals on the O2 sensor and any exhuast leaks - usually if the o2 sensor is bad it'll be well over the 0.8%.

Was the engine run in correctly ? See with a freshly run in engine you might not have booted it in a while - the old italian turn up thing

[Kirstin]

Hi Jonathan,

That sounds like a good starting point. The lady did burn oil before we rebuilt the engine and we have neither exchanged nor checked this. We will try that straight away tomorrow. Many thanks!!!!!

[Günter]

..Kirstin, habt ihr mal wenn alle Schläuche und Leitungen angeschlossen sind( und der Motor mit dieser ungewollten erhöhten Drehzahl von alleine läuft) den Motor im Bereich Enlasskrümmer und Kopf mit Bremsenreiniger eingesprüht -einfach um zu sehen ob er sich das Zeug irgendwo durch eine Undichtigkeit zusammen mit der Umgebungsluft reinzieht ..und dann eben merklich drauf reagieren würde. (for our UK friends : I refere about "unwantet air-bypasses")

ps. bei meiner (Nguyens)Else zicken die ganzen zusammengewürftelten Beuteteile derzeit auch rum. Hab zwar den MOtor mit seiner ganzen Umgebun inzwischen komplett bekommen (ist bis auf die Zahnriemenabdeckung nichts mehr zerbrochenes drann..) -aber der bekommt z.B. eben gerade zu wenig Sprit, und läuft damit nur in ganz kleinen Drehzahlbereichen (unter 800u/min) ..können wir ja gerne unsere 'Sorgen' tauschen

;D

Gruß

Günter

Edited April 18, 2011 by Günter

[Rich H]

get on ScottishElises.com and find a local MOT station that is a bit more 'understanding' about these little plastic cars....