S80 - Sometimes Running Rough.

AJS80 · Post by **AJS80** » 23 Feb 2011, 12:57

Some mornings when I start my 1999 S80 it will run rough until I get to about 20mph - The problem seems to vanish once Ive been driving a mile or so. Once the engine is warmed up there are no problems,and drives fine.

This doesn`t happen every morning, but when it does the message "Drive Slowly - Service Urgently" flashes up for about 5 seconds then goes off.

Like I said this doesn't happen every day, and hasn`t happened when the car has been started up later in the morning after been driven to work, or when started later in the day at the weekend when its not moved for 15 hours or more !!

I`ve changed the plugs and filter and put some petrol treatment (redex) through the system and its still occasionally happening.

Any suggestions as to where the problem lies would be gratefully appreciated.

Thanks.

Post by **jimmy57** » 23 Feb 2011, 13:59

From what you have listed my guess is a bad coil. Where is "Bolton"?
US spec cars will flash the check engine lamp but other markets aren't required to do that. Your message sounds like a non USA spec car and that message is probably the equivalent of USA spec flashing the check engine lamp for misfires.

AJS80 · Post by **AJS80** » 23 Feb 2011, 14:09

Bolton is in England,near Manchester !

Sorry for not mentioning the vehicle is UK Spec.

From reading elsewhere on the forum I think it may be an ETM problem !!??

Post by **jimmy57** » 23 Feb 2011, 14:13

It could be but your description mentions it is running rough and ETM usually just lets it idle roughly as it is canceling injectors to keep idle speed in reasonable range with no throttle opening via pedal or ETM allows limited throttle control with smooth engine performance but reduced power and delayed throttle response.

AJS80 · Post by **AJS80** » 23 Feb 2011, 14:29

Thanks Jimmy.

Whats getting me is that this only seems to happen on cold and/or wet mornings ie before 9am - and never happens later in the day,even when the vehicle has been sat on the car park at work for 8 hours or so.

Immediately after being fired up in the morning the revs will drop to 3000-4000 rpm, and the vehicle will sound rough as I pull away - but this doesn't happen every day ! When its like this and I get to around 20-30mph the "Drive Slowly - Service Urgently"
flashes up !