Help With Diagnostic

[nigel1971]

I have a 97 2.8 auto v6. It has just failed its mot on the emissons. I have taken it to 3 seperate garages who have all been unable to gain acess to the diagnostic's. Has any one else had this problem and what is causing it, as none of the garages have a clue?

[mumof4]

how many times did they do the emission test?..it is usually done 3 times but can be done up to 7 times before a fail is recoded.

[nigel1971]

It has been done three times so far. I have done an oil and filter change which has helped but it is at 2000rpm that the main fail is. The bloke at the garage can't under stand why at idle it is ok then fail then ok again.

[mumof4]

umm...3 times..is that one straight after the other?..or failed the mot 3 times.?

 

they can test the emissions up to 7 times on one MOT to get an average.

 

you could try blasting the car before it goes in for the MOT as the engine has to be a certain temp for the emissions test pus it will help.

 

why is he checking the emissions at 2k revs?

[nigel1971]

It has failed emissions 3 times on seperate days. Test results i have are: Fast Idle test RPM 3010, CO 5.915, HC 335, LAMBDA 0.830

Second fast idle:RPM 2920, CO 6.602, HC 364, LAMBDA 0.808

Natural Idle: RPM 641, CO 11.929.

I know the last reading is high but the air flow meter was not on, it is not that high now.

I hope this helps you as it is all gaga to me

[mumof4]

gaga to me aswell.....my gal has passed an emissions test with no MAF fitted.last year i think it was.yup..last year...

[whitty]

mum of4i think your missing the point his is petrol not derv! deisel and petrol tested in totally different ways and that kind of co levels is worringly high i'd be looking at the lambda sensor first (cos its a cheap and easy place to start! and cos it controls the fueling ) you didn't get a dose of that poo petrol when supermarkets had all those problems, did you??

[mumof4]

mum of4i think your missing the point his is petrol not derv! deisel and petrol tested in totally different ways and that kind of co levels is worringly high i'd be looking at the lambda sensor first (cos its a cheap and easy place to start! and cos it controls the fueling ) you didn't get a dose of that poo petrol when supermarkets had all those problems, did you??

 

Ah bugger..i did miss that bit entirely....<<note to self........take note of what model op has before replying!!

 

 

 

just scrap anything ive said in reply to this thread.

[nigel1971]

I don't think I got the duff petrol? Will be changimg the plugs later to see if that helps any. As for the Lambda, i only had a new one 6 months ago so i would like to think its not that, but cannot get into the car to see if there are any faults given. Many thanks for your reply's tho will up date to see if the new plugs do anything

[whitty]

i'll be honnest if plugs solve an emmisions problem that bad i'll eat my hat i think you have other e.c.u/sensor related problems i'd try the temprature sender for the ecu as well

[nigel1971]

Changed the plugs and leads (wot a game) and guess what. That's right Whitty your hat is safe it FAILED. mind you the co2 at 2000rpm is down to 1.7? back to the drawing board.

[gregers]

thats handy for whitty,his hat is a sombrero :ph34r:

[whitty]

it was a bold statment to make but i thought the hat was pretty safe !

[ALANC555]

Have you asked the garage to plug it into there code reader .A fault code would really help