Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[9mm]

My '99 2.5 has failed its emissions pretty spectacularly on CO and lambda.

I've had a read through this thread:

http://www.omegaowners.com/forum/YaBB.pl?num=1223977030

And I've done the paperclip test, which hasn't thrown up any error codes at all.

The car rarely starts on the first turn of the key, hot or cold, but will always start on the second or third, settles down fine and has plenty of poke.  All breathers are good and the car has done about 92,000 miles.  Things like oil, air and fuel filter are all quite new.

I'm puzzled as to how the car could fail its emissions but not be showing any fault codes.

Can anyone provide me with any advice, or even a checklist to work through?

Thanks

 

[rustym95]

how is the exhaust any leaks in it, you say it take 1-3 gose to start how long has it been doing this? they usually start first time. have the spark plugs been changed at all?

[9mm]

Hi Andy

It has done it for as long as I can remember - at least two years.  All plugs and leads were changed at around 70,000 miles, when the car had a pretty comprehensive overhaul - new cambelt, various parts of the breather system, HBV, cambelt and cam cover gaskets replaced, etc.  The car has done about 92,000 miles.

The rear boxes were also replaced and I can't say I'm aware of an exhaust blow.  That certainly didn't come up as an MOT fail and I wouldn't have thought the (thorough) tester would have missed that.  All replacement parts have been OEM.

There is one thing it has done for years and I have learned to live with it.  That is that it will hunt and often stall if the fuel cap is fully on.  Release it just a turn or so and it will run fine.  I've had the pump out and looked for crud there without success and then gave up on it, as it didn't seem worth the time to search for something I could cope with.

The emissions test has forced my hand though.  Without an MOT I am stuffed!

[dbug]

Italian tune up?

New MAF sensor?

[Marks DTM Calib]

Whats the temp gauge doing.....its clear that your tank breather setup is blocked!

Can you post the full emmissions results

[9mm]

Italian tune up?

New MAF sensor?

It certainly had the Italian tune up - triip to France and back in a day at sustained high speed.

MAF sensor is something I know that hasn't been changed during my ownership but it would that account for smooth running, odd starting and an emissions fail?

 

[9mm]

Whats the temp gauge doing.....its clear that your tank breather setup is blocked!

Can you post the full emmissions results

Temp gauge is normal.  No under or overheating problems.  I would like to know how to clear the tank breather setup, but have run out of ideas how.

Emissions results:

Engine temperature 80 degrees Pass

Fast idle test Fail
Engine speed 2890rpm Pass (2750-3250)
CO 2.57% vol Fail (0.30)
HC 178ppm Pass (200)
Lambda 0.932 Fail (0.970-1.030)

Second fast idle test Fail
Engine speed 2830rpm Pass
CO 2.1% vol Fail
HC 158ppm Pass
Lambda 0.945 Fail

Natural idle test Fail
Engine speed 630rpm Pass (520-780)
CO 9.69% vol Fail (0.50)

Overall result Fail

[Marks DTM Calib]

It needs live data....looks like the coolant temp sensor to me or its not reaching operating temp and entering closed loop control

Where are you?

[9mm]

It needs live data....looks like the coolant temp sensor to me or its not reaching operating temp and entering closed loop control

Where are you?

Near Littlehampton - south coast.

If the coolant temp sensor is cheap and easy to change, I'd happily give it a try.

If it's anything like changing the leads, I'd prefer pulling out my own fingernails!

[manny]

Blocked fuel filter can cause poor starting.You say its better with fuel cap off.