Jaaaag S type Misfire and engine management light.

[Vince70]

My old mans Jag has developed a misfire on cold startup and still runs fantastic once it’s warmed up but smells of petrol for the first couple of minutes and the engine management light has come up with a misfire.

 

I have a cheapo code reader and I’m getting codes PO300 to PO3006 which seems to be telling me what I already know is a misfire and I can turn the light off but on a damp morning it will come back up again and misfire again.

My theory is it’s getting oil or water building up in the plug wells so could do with a new camcover gasket or it needs a bit of damp start and a clean up around the coil pack but I just wondered if anyone has had the same experience with an old Jaag 3 litre.

[DodgeRover]

Try it with a different fully charged battery, slightly low voltage is notorious for throwing errors on them.

[oldcars]

As above my mate's had many a code. Battery was low, a charge up and it was fixed.

[Vince70]

Thanks for the info as it would make sense as my dad only uses the car once or twice a week to go to the shops.

 

He didn’t use it for a couple of months so the battery went flat so I put it on charge just enough to get it to start and this time of year it’s got all the gubbins on such as the heater etc.

[Broadsword]

Fresh battery, a large dose of Liquid Moly with some good fuel in the tank and a blast down the motorway is a good bet. No old Jag likes sitting around.

[Pete-M]

Change the plugs.

[bangernomics]

Second/third the battery. Well worth buying an optimate if you own a jag.