V6 missfire.

goldfinche · Post by **goldfinche** » 01 Jun 2006, 11:27

Hello I have a 1997 (August ) Xantia V6. I have replaced the sparking plugs and 3 plug leads. The problem is that when the engine is hot, on tickover, it feels and sounds as if its running on 5 cylinders sometimes. It is definately getting more notisable. When the tickover is raised it "clears" and sounds OK. I am guessing that it is not mixture related but it is only a guess. Are there any simple tests I can carry out , I dont know a lot about injection motors.
It has aircon if that makes any difference and has done 51,111 mls.
Thankyou for any pointers you may be able to give.
I will not go to the Citroen dealer, they supplied Dexron fluid for the gearbox (4HP20) ,which I did not put in thank goodness and when questioned replied "ITS ALL WE CAN GET" Thanks a bunch.
Cheers and thanks chaps.
Geoff.

f00lzz · Post by **f00lzz** » 01 Jun 2006, 11:53

Hi. Did you change the plugs and leads because of the missfire... or is it now missfiring since you changed them?

8304 · Post by **8304** » 01 Jun 2006, 14:24

my dads v6 xm was doing somthing similar.

i changed the rotor arm on it and it cured it.

the problem was the spring behind the springloaded contact in the centre of the arm had failed alowing the contact between the arm and cap to be broken causing a misfire...

good luck

goldfinche · Post by **goldfinche** » 01 Jun 2006, 14:29

Hi thank you for the reply.The plug leads were changed because I knew they were the original 1997 ones and thought I would start with something simple to see if it would cure/improve the missfire, it didnt. So the simple answer is that the miss was there before the lead/plug change.
I was hoping that it was not the coil pack going down.I would hate to think how much that would cost!!!
It does start vertually instantly it is only when it gets up to temp the problem starts.
There is no warning lights warning of anything.("K" light etc.) Its running at the usual temp.
Thanks and cheers.
Geoff

Post by **xantia_v6** » 01 Jun 2006, 19:33

I haven't had any similar problem with my Xantia V6, but from experience with other cars, my check list would be:
1. Coil pack
2. Air leak in manifild causing one cyliner to run lean
3. Sticky/blocked injector

You might try clipping a timing light onto each of the HT leads, if the coil pack is dying, you should see the timing light misfire in time with the engine misfire. Also try running the engine in the dark with the top cover off the engine, you might see some lightning around the coil pack.

Good luck.
Mike

goldfinche · Post by **goldfinche** » 01 Jun 2006, 22:32

Thankyou very much, I will see what happens in the dark and if I can get my timing light back from my son I'le give that a go as well.
Cheers.
Geoff.