8 replies to this topic

[Elwyn]

Hello

I've been doing things on my car

It's taken / taking ages

The battery was disconnected for months

Now all back together

Started the car

It did start 

First time

It's running very lumpy

I've read that the ECU will have lost its memory and it takes a while for it to relearn what to do

Is that right?

During this relearning period, with the car running lumpily (rich), the catalytic convertor is getting red hot very quickly

Glowing red 

I assume it's not good for the cat?

Is there a way round this or is there something else at play here?

 

Thanks

 

 

[Elwyn]

sorry, 1993 L reg SPI Cooper

[Tones61]

Air leak,
Poss vacuum hose's perished or left off?

[xrocketengineer]

There is another possibility. An air leak at the manifold to down pipe joint, right next to the O2 sensor. If there is an air leak the, sensor will read it as excess O2 and it will dump extra fuel that will burn in the catalyst. 

[Midas Mk1]

They can get blocked up.

[bluedragon]

It is running far too rich. The catalytic converter is reacting with the excess fuel, and that combustion is making it glow red. You have to resolve the cause of the excess fuel - it's far beyond the programmed boundaries of the ECU. If everything else is correct, it will not command that much excess fuel under any circumstances.

 

I'd resolve it ASAP. It's not good for the cat - the matrix inside is fully capable of melting, if it hasn't already. Not to mention what might happen to that much heat being radiated into the floorboards and other nearby components. And if you park over some dry grass....

 

 

Dave

[Elwyn]

Thanks all

Leaking exhaust system seems to be the culprit

At the manifold gasket and from catalytic convertor to rear exhaust system

[xrocketengineer]

If you need to use  a sealer on your gaskets, do not use any containing silicone. It is not good for the sensor nor the catalyst. Use something like Permatex 80335 that contains sodium silicate. It can be thinned with water and it cures into "glass" with the exhaust heat.

[Steve220]

It's running lean, which is creating the heat. Running rich just blocks them.