Calais V6 Misfire??

[A+d+a+m]

Sup

My Vs Calais seems to have a problem in the electrics of the motor. this problem comes and goes depending on how hot the car is or how much driving it has been doing.

usually after about 15 minutes of driving the car will start to struggle to move when u need to accelerate. then it makes a sounds that i can only describe as similar to a misfire, it continues to do this until i stop the car and let it cool down or manually change the gear to give the engine higher RPM. doing that does not solve the problem but just makes the motor able to move the car even though its "misfiring". the whole car shakes when it does this and the RPM does not rise no matter how much throttle the car is given until the gear is changed manually. my guess would be a coil pack or a lead. a friend said maybe the fuel pump. i just wanted to see if anyone else had this problem before, and what i have to do to maybe solve this problem.

oh by the way the Calais is a V6 Ecotec with 104XXXKms, don't know if that helps

thanx

[hako]

Try checking for fault codes first: Checking error codes VR/VS (Revised)
But apart from that it sounds like either leads/plugs/coil(s) or the dfi module in that order. It's all a process of elimination.

[A+d+a+m]

DFI module? soz im not good with all the tech electrics in these cars

[A+d+a+m]

The fault code flashed like this, Flash (pause) Flash Flash. then repeats which i think means code 12?

[hako]

OK - that's a 12 which means no logged faults. So next thing is to inspect and replace items. The idea here is to replace items which can cause the problem you describe - the best way is to start with the ones that are common fail items (also the cheapest). So first cab off the rank is plugs and leads - they should be replaced every few years and are a common sense item for just routine maintenance....so I'd get a set of NGK plugs (about $25 for 6) and a set of leads (about $50 to $70) and replace them first. All up this will cost under $100 and may or may not fix the problem but if not then you will know that leads and plugs are in first class condition. You instal these yourself and save about 1 hours labour for a mechanic (~$100)
So I'd try that first and see how it goes. Good Luck.

[A+d+a+m]

I Replaced the Plugs and Leads, the car seems to be running fine now. from the looks of it 2 plugs have been burnt quite badly. so my guess is that was the problem. but since i replaced the leads at the same time i will never know haha

thanks for your help mate

[hako]

Think about it - if two of the plugs look like they are burnt badly there will be a reason why they are burnt! It probably would be due to the leads breaking down and not firing the plugs which then causes the plugs to foul up and possibly look burnt.
You did well.

[jashdown91]

I've had this problem about 6 months ago. Replaced the spark plug leads and it eliminated the problem. One of the leads may be causing a spark plug to misfire when you put your foot down. If you dont want to replace the leads, you should check the current through each lead, to make sure they are all in correct working order. If leads aren't the problem then most likely spark plugs. If that's not it, then you may have a more serious problem.

[A+d+a+m]

the leads did look really REALLY old. how would i go about checking the current on the leads? i have heard its like lifting the lead off the coil pack and letting the current jump. the one with the least distance in the jump is the broken one? which would mean that something else in my car is causing the burnt out plugs

[hako]

If the leads look really old then I wouldn't even bother checking - I'd just replace.
However, if you wanted to check them you need a digital multimeter and then you measure the resistance of each lead....they must have a certain resistance otherwise they must be replaced.
The old method of pulling a lead and seeing how big/bright the spark is not the proper method - voltages are so high you'll get a boot from the lead so strong you'' think you've been wrestling with King Kong.

[subieboy]

Mine turned out to be the centre Coil of the three

Pulled and replaced, no dramas since

[A+d+a+m]

Oh true. good thing i didn't try the old method then. yeah i ditched the old leads. they were no use to me and i didn't want to risk making things worse by using them on anything.