Vs V8 rough Running

[pikey]

Hi all
I have a VS V8 and when the car is warm it has an intermittent problem where it seems to be running on 6/7 cylinders. It can do it on idle or when on the move. It seems to show up more on low revs. Any ideas where to start looking?.
Thanks

 

[moneypit]

Buy new plugs. Take out the old plugs and arange them on a table,bench in the order they come out of the engine. Like in 2 rows of four front to back exactly like they come out.
Then put the new plugs in. If that doesnt fix the problem, post up a decent pick of the plugs you pulled out, that should help see whats wrong. Include how many Km's and any recent service info.
With the info you suplied so far it could be anything.

 

[pikey]

Thanks for your reply..I have now replaced the plugs and the fault is still there..All the plugs i removed all look in exactly the same condition. The car runs fine when cold but the fault seems to start after maybe 5 k's. Any ideas what i should be replacing next?
?

 

[moneypit]

Well if I had to guess I would say change the ecu temp sensor next ( the two pin one front of manifold) as it could be running rich when warmed if that's not working. Could also be the O2 sensors or ...... so yeah half a dozen things really, sorry.
However a service manual has trouble shooting guides and test procedures for the sensors, so really that would be my next purchase.

 

[harrop.senator]

Warmer electrical items face heavier resistance. Sounds like you may be experiencing spark break down could be coil , ignition module , hall effect sensor in the distributor or even a crack in the dizzy cap that gets worse with the heat expansion. If you have friend with any spares and known working items id try one by one swapping and see if the issue clears up.

 

[BlackVXGTS]

Ignition-related heat symptoms of an intermittent nature seem to be more due to the Hall Effect sensor in the distributor, although they normally cause the engine to stall, and able to be restarted once the engine has cooled down. Ignition coil and ignition module (in my experience) tend to be hard failures when they occur. Having said that, my VS Calais had a strange miss when it was new, and it wasn't until I upgraded it to a 355, that I found out the distributor->coil lead was faulty. Your VS is probably due for a lead replacement anyway, so that may be a good next place to start. While you are at it, check out the condition of the distributor cap and rotor.

 

[pikey]

Hi all

Thanks for all your advice...I have finally got around to replacing the leads, suggested as one of the possible causes and it now runs like a dream again.
Thanks