Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Help diagnosing Zetec running problem please

Glad it is sorted

Hooray! And thanks….Nice to be lucky once in a while!

Great news

However, as you rightly say, why it degraded after just 20k miles is the important question here?

If the engine has been running excessively rich the unburnt fuel will have built up in the cat, and when that fuel lights off it'll create a rather effective kiln which will soon break down a cat matrix, I've seen catalytic converters glowing cherry red when this happens.

The Omex logging feature will help you confirm or deny an excessively rich condition 'lambda feedback', it'll also immediately show if your lambda sensor itself is working? Keep in mind an excessively rich condition will quickly contaminate a lambda sensor leaving the ECU to fall back on the open loop fuel table, which itself may have been calibrated on the rich side.

Also, check the 'fuel cut on overrun' feature is active, typically this is only active above 2,000rpm to avoid drivability issues, but if its never been activated at all you can end up flooding your cat when you lift off the throttle, especially if the fuel table has been calibrated on the rich side in the decel/low load cells.

It's definitely worth spending some time investigating the route cause of the issue, and before you cook another expensive cat

Thanks, I’ll take a look at that, particularly the fuel cut on overrun - that could make sense as the map on there does produce much popping and banging on the overrun, fun in the first few months but definitely a bit excessive sometimes!

Any recommendations for a good tuner who is familiar with Omex and zetec engine would be appreciated, I am based near Southampton and feel like once the new cat is fitted a remap could be beneficial?

I have sent you a P.M. that may be of use. (Look for the flashing envelope by your name when you sign in.)

Omex is now owned by Frontline, the MG people.

Tim or Connor at Frontline will be able to point you in the right direction.

Dave.