Miss firing etc

[GQJays]

Hey guys, I'm having some issues with my TB42...it is running fine until it warms up then I notice it missing and carrying on when its under labour, mostly in 3rd gear if revs aren't high enough...any ideas for me to check out??? Thanks in advance.

Jays

[threedogs]

Are all your vacuum hoses Ok. also check for leads breaking down {sparking}
Night time best for that one

[happygu]

I would change your spark plug leads first up, as it sounds like one is dodgy......

How old are they?

[Parksy]

Check the things that are heat related. Ie, valve clearances change as the engine warms up, carb fuel mixtures etc. have heard of the ballast resistor on the ignition coil causing issues when warmed up.

[GQJays]

Thanks guys...will check all the leads etc...not too sure how old they are as I have only bought the car a month or so ago, this only started to happen yesterday when I noticed some pre-igniting...i down tuned it, moved the distributor anti-clockwise about 2mm but started missing really bad, I put it back to where it was but still have the miss-firing but not as bad, it has no pre-igniting issues now though haha...also runs sweet until it labours eg; third gear at too low revs, coughs and splutters etc