Random misfire when driving...

[Ben Lessani]

I had a search and this fella here had the exact same issues...It doesn't happen all the time, it only ever happened once, then recently it happens about once every 1.5hrs of driving. The engine just drops all power for about 1s then powers up fine, otherwise the car pulls like a train through the whole rev band.

Only trouble is, how can I tell if the dizzy rotor arm is worn (I'm not sure what to look out for)?

[BIG D]

check for carbon it should be brass but if its black give it a clean the cap will be the same

[Diamond Hell]

Check your earths - I had this in my Syncro a while back - it was just a dodgy earth.

[Ben Lessani]

Stupid car did it again on my way back from the gym.

My earth's are pretty mint - just renewed them with 2awg cable, but I will pull them off and give them a clean again. Will clean the rotor arm up too and see how it goes.

[dan23]

my car is doing the same sort of thing mate, iv been told its water or condensation getting into the dizzy cap

[Ben Lessani]

Well, I cleaned up the dizzy cap with some WD40 - the contacts seemed pretty clean anyway. I looked at the earth's on the rocker cover, and it was pretty crappy - all oilly and a little loose. So I went nuts with the dremel and polished everything back to a nice shine, re-attached it all and tightened it and smothered it in grease. Double checked the battery -ve and +ve feeds and they're still mint...

...I drove for about 1 day without noticing it, then a tiny blip of no power again.

[Diamond Hell]

There's a group of earths above the fuseboard under the dashboard - make sure they're all in good nick - stuff like the fuel pump relay earths up there.

And use Servisol on your electrical contacts, not WD-40 (useless bloody rubbish).

[Ben Lessani]

I will have a lookie today. Servisol - isn't that butane? I was using the WD40 as a dispersant incase it was water in the dizzy.

[Ben Lessani]

Goddamn it! Driving home and now the mis-fire is developing into a flipping backfire, engine cuts out, revs drop to 0 on the dial, nothing for 1-2s then BANG, engine fires back up again, why is this suddenly happening. The only thing I have changed recently is the type of oil I'm using, with my leaky valve seals and rings - it could maybe be that its burning funny - I dunno, very confused.

Edit: I'm starting to think this might tie in with the car starting difficulties. Every so often, I turn the IGN and the starter clicks once and does nothing, a few more times and the car will fire up as normal. Seems pretty random, one of my immobiliser's is spliced into the starter circuit, perhaps that could be the cause? I will have to have a once over of the fusebox grounds as advised and see what it turns up.

[russ-vdub]

just checkin, when was your last service? Have you checked all you leads are plugged in correctly. It sound like a spark ignition problem to me, Could be the coil arcin across to the neg, happened to me due to a crappy connector. Insulated it went away.