'Orrible smell from my B3 90 20v.

[SwallownAmazon]

Just back from a very enjoyable "no pressure" trip around the countryside of the Pas de Calais which we normally only see from the rally car while competing.

The old girl performed faultlessly apart from one thing and that was the smell from the exhaust. It smells as though it is running rich although overall fuel consumption just trundling around was 35 mpg, perhaps a little bit higher than I might have expected but not bad for a 2309 engine. Several of our fellow travellers on the holiday commented about the fumes after following us and it was noticeable that some tried to get by or just dropped back.

I have noticed that the temperature gauge rarely goes above the division between 50 and 90 degrees even though the temperature at the top of the rad when the engine is hot is around 86 degrees. This was measured with an accurate temperature probe I used to use for work measuring the temperatures of paper mill drying cylinders.

A couple of things come to mind but I would seek advice as I am a bit of a bear of simple brain in such matters:

• Does the same sensor operate the water temperature gauge and send signals to the ECU or are there two? If it is the same sensor could a low "reading" cause the ECU to call for more fuel? Are these sensors still available?
• Could a faulty lambda probe cause over-fueling?

Injection system is the Hitachi version if that makes any difference.

[John.]

Originally Posted by SwallownAmazon

...Does the same sensor operate the water temperature gauge and send signals to the ECU or are there two?

I seem to recall there's a temp sensor on the back of the head above the plastic water pipe?

[mikes2]

Are you catless on that or is it still fitted ?

Temp gauge senders can be a bit problematic - they read fine at idle and then drop on the move. Very much like failed thermostat behaviour.

As John has indicated, the ecu sender is at the rear of the cylinder head. Very reliable and if it fails, it will throw a code

[sjp001]

No fuel leaks anywhere? Sometimes it might only leak when the engine is running when it's being pumped.

[Davids]

Have to say I have noticed the same now and then on the Coupe, 2.3 20V

Cant find anything wrong, plugs look great, always passed the MOT emissions.

I still have the old injectors as well, just wondered if it could be them, having done 160k.

Get average 28 to 32 mpg, never any better

Changed the rear box wondering if it was blocked as it rattled a bit but made no difference.

Would be interested to see if you find anything

Cheers

David

[SwallownAmazon]

Originally Posted by sjp001

No fuel leaks anywhere? Sometimes it might only leak when the engine is running when it's being pumped.

Not a "raw" petrol smell, it's like a "rich mixture" exhaust smell. We did have a perished fuel line a couple of years ago but they've been replaced with fabricated replacements and no sign of any leaks now.

[SwallownAmazon]

Originally Posted by mikes2

Are you catless on that or is it still fitted ?

As John has indicated, the ecu sender is at the rear of the cylinder head. Very reliable and if it fails, it will throw a code

Hi Mike,
Yes, it still has the cat fitted and the emissions are well below the MOT spec even though they don't actually apply to my car.
I don't have a code reader so it looks like it's back to my pet garage to properly investigate. If anything is thrown up, I'll post up to let "Davids" know.

[Davids]

Originally Posted by SwallownAmazon

Hi Mike,
Yes, it still has the cat fitted and the emissions are well below the MOT spec even though they don't actually apply to my car.
I don't have a code reader so it looks like it's back to my pet garage to properly investigate. If anything is thrown up, I'll post up to let "Davids" know.

Cheers

[mikes2]

They do tend to run on the rich side.

Possibilities

carbon canister
injectors
lambda - they don't usually throw a code

if you can smell it inside the cabin, check the fresh air flap in the bottom left corner of the boot - they're usually broken

On my car, a wrong fuel pump relay caused fault codes for the lambda probe + both carbon canister senders

[Davids]

Originally Posted by mikes2

They do tend to run on the rich side.

Possibilities

carbon canister
injectors
lambda - they don't usually throw a code

if you can smell it inside the cabin, check the fresh air flap in the bottom left corner of the boot - they're usually broken

On my car, a wrong fuel pump relay caused fault codes for the lambda probe + both carbon canister senders

Thanks for the tips, where is the carbon canister ?