Shaking/misfiring in Drive

[joeboss]

Hi guys, did a search but couldn't find anything to help me out.
I've had my 2003 Monaro CV8 parked up this weekend and jumped in it and drove for about 20 minutes with no problem.
I stopped for about 5 minutes and when I started it up it was shaking and misfiring pretty badly. It's not as bad when in neutral but when in drive and reverse it was bad. Entire car shaking and pretty bad coming through the steering wheel.
Did check plugs but they are fine and only 5000kms old.
I'll take it down to the mechanics during the week, but I was wondering if anybody had any ideas what it could be.
Thanks in advance.

[D_BLOCK]

I would double check those leads, I had that happen but I had switched to after market leads and some how the damned things would slip the very
back driver side lead off. Hate for you to pay a mechanic for a simple solution, worth a shot.

[Mohit]

I had the exact same issue with my VY Calais LS1 about a year ago and found 3 of the ignition leads were split in the insulation at the rubber boot join.

Replaced with a new set of MSD ignition leads and no issues so definitely worth checking.

[Evman]

You can see if it's an individual cylinder causing an issue by removing the connection to each coil pack one at a time (not the plug lead, you'll get zapped bad, the other electrical connection). Find one that doesn't make a difference to the way the car is running and you'll know it's either the coil pack, lead or spark plug.

[Big_Valven]

Leads should be changed when you do plugs.

[BLACK 346]

Leads should be changed when you do plugs.

I change the plugs in my Commo every six months, doubt I will be doing leads that often. The wifes Rex had a new set of Iridiums after 3 years and 50k the other day, guess what, still the same leads. I can understand breaking the OEM leads whilst pulling them off, especially if they have been on a while, but a good set of aftermarket leads will last for years.

[cashie]

No need to use aftermarket leads, the genuine leads are very good quality (generally better than most aftermarket leads).

To the OP, yes, reseat all your leads and see what happens.

[morphix]

Does the issue seem to go away when you are full throttle or does it get worse?

[joeboss]

Worse when getting onto the throttle. I checked the leads and they seemed fine. Didn't get to the mechanics today.

[JezzaB]

Does it do it cold and at idle? If so:

If you wanna delve a little further yourself at home quickly and you have aftermarket extractors. Start the car for 2 seconds tops from cold. Touch each extractor (be careful they arnt hot). The ones that are cold and not warm, arnt firing...... Not everyone owns an IR temp gun

[Big_Valven]

I change the plugs in my Commo every six months, doubt I will be doing leads that often. The wifes Rex had a new set of Iridiums after 3 years and 50k the other day, guess what, still the same leads. I can understand breaking the OEM leads whilst pulling them off, especially if they have been on a while, but a good set of aftermarket leads will last for years.

6 months isn't exactly a normal service interval for quality spark plugs on a healthy near-stock engine. Do we seriously need a disclaimer that advice may not suit your circumstances? Jesus.

Worse when getting onto the throttle. I checked the leads and they seemed fine. Didn't get to the mechanics today.

Visually yes but when you're dealing with HT lines insulation can break down as can conductors. It's the easiest part to substitute.

[BLACK 346]

No need to use aftermarket leads, the genuine leads are very good quality (generally better than most aftermarket leads).

To the OP, yes, reseat all your leads and see what happens.

Yes, your are right, some of the factory leads are very good, and definitely would not need changing with plugs, even if you leave the plugs in for 100k.

[BLACK 346]

[QUOTE=Big_Valven;2079472]6 months isn't exactly a normal service interval for quality spark plugs on a healthy near-stock engine. Do we seriously need a disclaimer that advice may not suit your circumstances? Jesus.

No need to do a gasket champ. You shouldn't need to replace leads even if you are stupid enough to leave plugs in for 100k. Just be a bit more careful when removing them. Our Rex still has stock leads after 150k and they are fine. Hate seeing people just replacing shit for the sake of it

[joeboss]

Well I had another fiddle with the leads and it seemed fine. I drove to Nowra from Sydney with nil issues so whatever I did must have worked. Thanks for the advice.