That dreaded intermittent fault.

[Tom1964]

Hi guys, quick question to see if anyone else has e prettier need the same fault.

For the last couple off weeks when starting the car from cold the revs go up to 1250 and the engine runs a little off. Not a proper miss fire but just a tad lumpy. Exhaust sounds louder than normal but it only lasts around 30 seconds and clears. Within a minute the engine is down to 750.
Doesn't happen when warm and may be every other start up. Had new coil packs and plugs and have run an injection cleaner.

Anyone experienced the same and if so, what was it ?

[Cuprabob]

It's perfectly normal.

At certain ambient temperatures and coolant temperatures the ECU changes the fuelling in order to get the cats upto their optimum temperature quickly. Some cars use Secondary Air Injection (SAI) but the 1.4 (160) does it by changing the fueling. It only occurs for a few mins and only when specific parameters are met. It's basically to help with emissions during a cold start.

Have a read of Blower's post in the following thread.
http://www.sciroccocentral.co.uk/forum/ ... 11#p208011" onclick="window.open(this.href);return false;

[Tom1964]

Thanks cuprabob. That makes a lot of sense. Most mornings it is fine, which if it was a cold start issue you may expect. Generally it mainly happens after i have finished work around 5pm and the temps are up to their 20+. Once again you have come up trumps.