D22 petrol misfiring when engine is warm

[Dunno3624]

Hi Champs,

I’m wondering if someone can give me some advice on the following issue that might have happened to them. There are some great threads about this, but no one has replied what the fix is. My 2003 V6 D22 runs like a dream when the engine is cold. When I drive it down the road, the only issue is the battery light is still on. As soon as this turns off (within a minute or so....by this time the engine is warm) the engine starts surging/misfiring. The needle on the tachometer bounce’s around 1-2K RPM. The surging / misfiring gets so bad that it can’t be driven, even in first gear. I understand that it is most likely electrical, but would like to hear from someone who previously had this issue and what they did to sort it.
Cheers

 

[Been a while]

Make sure your fan belt is tight! Check alt output, clean battery terminals.. code read, etc

 

[Old.Tony]

It sounds like it's more likely a dirty connection. The alternator light shouldn't be on once the engine is running - it should go out immediately. Here's one test you can do to ensure the alternator is working properly: in the morning, pop the bonnet before starting and test the battery voltage with a multimeter. Start the car and test it again. Voltage should be in the low-to-mid 12.x range before starting (healthy battery getting good charge during operation) and should be low-to-mid 14.x while the engine is running. A small variation is acceptable (down to about 13.8V).

If your battery voltage when idling is below 13.5V then you may have either a failing battery, a slipping fan belt, dirty connections from alternator to battery (including the earth from battery to engine, and alternator to engine) or a faulty alternator.

I'd do some measurements and some cleaning and see what happens from there.

 

[[email protected]]

being petrol with spark plugs are leads perished, if you lift bonnet at night accelerate the engine ,you may see a light show happening where the leads are leaking. happened to my commodore

 

[Dunno3624]

I have just had the alternator replaced and that has taken care of the battery light. Engine still surges though. Leads etc all look really good. For the first time tonight the car just wouldn’t start. Finally got going and it was suggested that I replace the crank angle sensor. What is everyone’s thoughts on this suggestion?