How to test vy ignition coils with multimeter and other advice for shuddering 03 v6 vy

[yz300]

Hi everyone. I have an 03 v6 ecotec. Wife told me it's losing power. Took for a spin, I'm suspicious of the ignition as it shudders on acceleration on petrol and gas. I think it's been a while since i did plugs and leads but want to see if there's a way i could check the ignition coils with a multimeter too, to rule that out before pissing round with plugs and leads. So would anyone know a way I could check the coils? Seems strange to've just happened all of a sudden. I could even feel it missing when I gave it some pedal in park from idle. Could a sensor or connection on a sensor be causing this? Any thoughts? Please feel free to ask for more information if you need it, I'll be happy to provide it, I'm just looking for a quick fix for my wife here. Good advice will be taken on board, make no mistake. Thanks, Gus.

 

[87VLCALAIS]

I'd be leaving checking the coils for now. If it idles OK then I'd say the coils are likely to be OK.

Sounds like the insulation on a plug lead breaking down, but first check that the plug leads are properly fitted to the plugs and that the ceramic part of the plug where the leads fit over is clean. Next I'd whip out the plugs and check them for carbon and correct gap.

If it still happens and only happens under acceleration then I'd look at the leads. They can be tested but you're unlikley to have a Megger or similar to test them properly. If they've been on the car a while I'd seriously think about new leads and just for good measure new plugs as well.

If it misfires at idle, then, start removing plug leads one at a time until you find the one where there is no difference when you remove it. I would recommend not removing the plugs while the car is running. Then you'll need to figure out if it's a plug, lead, coil or DFI module. If you get to this point and need more help post back on here.

 

[losh1971]

How old are the plugs. The V6 burns through plugs faster than many other cars, as they run a wasted spark system. I found 25-30k was about the life of plugs in my old V6.

 

[Immortality]

Yup. Plugs and leads?

You can do a resistance test on the coils.