Failed Emission test UPDATE

[Dave Rothwell]

Dear All,

 

I posted this the other day,

 

 

 

 

’ve just taken the car for the test and it’s failed the emission test.

 

The car is a 1999 Superlight with a standard 1600 Supersport K series. 26000 miles.

 

I’ve had the car ten years and it’s always passed the emissions until last year when just prior to the test we changed the timing belt. At the same time the guys put their dial gauges on the engine and said the inlet valve timing was out and reset by one tooth which then made it spot on (which I am sure was correct as the club members that did it for me know their stuff)

 

The car then ran great, tick over was lumpy which I was told would be the case, and a wiff of fuel on tickover. Took it for the test and it failed emissions completely. The tester said change the lambda sensor which I did and it the passed no problem.

 

 

This year it’s got the tickover fuel wiff again and it’s failed the emissions just like last year.

 

As I am a complete numpty on engine stuff I wonder if anyone could point me in the right direction.

 

I could always change the sensor again and see if it passes but it seems a bit coincidental if it’s broken another why would that happen ?

 

I have booked it into a guy with some diagnostic gear for Monday AM to see if he can plug into it so if anyone could give me some idea of the ECU settings he should be looking for that would be really helpful.

 

Sorry if I’m making this sound easier than it is – I’ve no idea with all these electronics – bring back carbs and some points say I (NOT).

 

The cat should be fine as I only put it on for the test then take it straight off again !! It’s probably only done ten miles.

 

Apart from this the car always runs great and I always get approx 40 to the gallon even when pushing along.

 

 

 

The UPDATE is I think the problem is solved- I took the car to a local guy with diagnostics and he plugged his gear in and said the inlet manifold vacum was very low on tickover whic was affecting the ECU. The Lambda and oxygen sensor were working fine. He said this could easily be caused by moving the inlet timing as described above so we took the belt off and moved it back one tooth and hey presto - reading now spot on.

 

Taking for re-test tomorrow. How did it pass last year - urrm good question.

 

Anyway if you live in the North Manchester area and need a diagnostic guy He's called John Smithson in Haslingden on Hud Rake Road and he was really helpful and had the gear.

 

Many thanks for the replies,

 

daveR.

 

 

[oilyhands]

You need verniers..

 

Oily

[EFA]

Hmmm variable cam timing for MOT compliance. The Anoraks will love that!