I was driving at about 70 yesterday when my car started running really roughly, thirty seconds later the cel light started flashing.
I was only a mile or so from my office to I carried on rather than leaving the car at the side of the road. After getting the AA out, the mechanic read code P1399. He checked the spark plugs and leads and all looked ok, then said all he could do was get the car recovered to a garage, which they are going to do on Friday.

There were no other codes to tell me which cylinder is misfiring - can I pull the coil packs out one by one with the engine running and how common are coil pack failures? I'm not convinced that it is just on one cylinder however, I think the engine is misfiring on all four clyinders.

Can anyone suggest other things to check before I hand it over to a garage for an expensive game of parts replacement? It was running fine before and has never had a misfire problem in the past. The cel light is off for the first 20 seconds or so after starting the engine, then starts flashing. You can smell petrol comming out the exhaust.

All the searches I've looked at, code P1399 has been given along with other codes or has started intermitantly.

Any help will be greatfully recieved.

Cheers

 

disconnect each coil pack individually and see if it affects running. dont remove them from the sparkplug; disconnect the connector itself.
if there is no change then you've found the issue on that cylinder.

a change in engine behavour denotes a good cylinder.

 

Cheers, I'm going up to the office tomorrow, so will give it a try. Hopefully it'll turn out to be a coil pack as this appears to be the cheapest and easiest out of the possible causes. Just gotta hope I've not overheated the cat..

 

Find a friendly owner near you and swap their coil packs on to your car.

If still there after that I'd go with the possibility of blocked injectors - dodgy fuel maybe?

How much was in the tank when it happened?

 

I had a similar problem last year and it was one of the coil packs that had failed.I now always carry a spare.

 

WHS.

If you can get it to consistently misfire at idle, try the coil pack trick to work out which it is. Then swap the coil from the offending cylinder with another one and see if the fault follows the coil. Don't expect the fault code to accurately tell you the cylinder number, because it won't.

 

That's a pretty sensible idea, eS!

Doing the valve clearances cured my misfire codes.

 

Cheers for the replies - I've just tried it and the fault was on no.2 and moved with the coil pack, so I'm off to get hold of a new one.

I'll find out at my mot in two weeks if the cat overheated...

 

New coil pack fitted, running smooth again. Doing an ecu reset to clear the fault code, then hopefully all's ok.

 

Good news