Car running weirdly

[Patty]

The leads can be tricky if the insulation is cut/melted or otherwise causing them to ground. If you played around with the leads you could have done enough to stop them from grounding but the 'problem' would still be lurking...

[philz]

I didn't actually touch anything yesterday, but I've got someone coming over with some leads, to see what happens, but it's working fine again

edit:

I thought that I would touch the leads, pulled them out, then plugged them in, and now it's misfiring....so right now it looks like its the leads, will update this afternoon.

[philz]

changed leads, same misfiring happening, engine sounds like a tractor/boxer engine..

Took out spark plugs, looks like the outside is corroded, but the igniter looks normal.

Will buy some new spark plugs and see how we go from there, if not, it could be leads again.

[silvermiata]

i had pretty similar symptoms with my car, and it ended up being a faulty petrol pump.

Unfortunately there are many parts that could cause the same issue...

you might even want to check your airfilter.. there might be something sucked in there..

[philz]

$14 later, it's the spark plugs.

Started her up, started to misfire, oh noes! it's not the plugs... 2secs later, it started to idle normal.

Thanks to all, and to MXHEVN for coming out today to lend me some leads.

edit: it's misfiring again, it's probably leads now.

[philz]

Okay my car is temperamental.

This morning, it started fine again.. no misfire

This is the same thing that happened yesterday morning, when I had not touched anything.

and note: It's not hot here in Sydney, and there is no CEL light

[Garry]

there is no CEL light

How do you know? Have you plugged a LED into the diagnostics box to check for fault codes? Early AUS delivered cars dont have a CEL on the dash.

[philz]

Thanks, I just realised that it doesn't have one

[JBT]

Make sure the (new) plug wires are pressed fully home. If that does not fix it, start thinking about coils and/or broken loose wires/plugs at/from the sensors.

At 78,000km it should have had a new fuel filter by now I think.

[philz]

Cheers will do.

Just ordered some servicing parts:

New plug leads
Fuel filter
Air filter

Will be checking all of the sensors this weekend.

So this morning it started properly, but now its misfiring again. This morning it was nice and cool, now the car is in direct sunlight, and it's probably heated up the car, hopefully it's not coilpacks.

[Guran]

[silly hat]

I know your problem. Have you noticed that every time you announce that you've fixed the problem, it miraculously rears it's head again? Maybe you shouldn't tell us you've fixed it. That ought to do it!

[/silly hat]

Seriously though, it's been enlightening hearing about this issue and the variety of steps you've taken to address the problem. It's given me a healthy respect for the difficulty of diagnosing faults.

[philz]

[silly hat]

I know your problem. Have you noticed that every time you announce that you've fixed the problem, it miraculously rears it's head again? Maybe you shouldn't tell us you've fixed it. That ought to do it!

[/silly hat]

Seriously though, it's been enlightening hearing about this issue and the variety of steps you've taken to address the problem. It's given me a healthy respect for the difficulty of diagnosing faults.

HAHAHAHA, mate I know what you mean, I've actually noticed that

Will update it regularly, doing it step by step, I have a funny feeling it's gonna be the leads [ and I really hope it is], as I would have turned a big problem into something farily simple... hopefully.

[philz]

Okay, replaced air filter, and new leads now.

Problem still occurs.

Engine doesn't violently shake as before, still a bit of movement but it still misfires, probably helped by new plugs and leads.

Though when I'm idling @ 1000rpm, it misfires, rev it to 1500rpm misfires/shakes more, then at 2000rpm the engine is more stable.

I haven't done a test run yet.

Again today the sun is super hot (weather is quite cool), just changing the plug leads < 2mins in direct dunlight, I broke a sweat.

edit: So now it rounds it down to sensors and coilpacks?

EDIT AGAIN:
It seems as though, my misfiring has stopped, the engine does not vibrate as rough as before, and the engine sounds like normal.
However my exhaust, does still sound like an old tractor wrx thing.
So now I'm thinking it could be the O2 sensor, or a plugged cat ( due to driving it with a misfire..but I have only dríven with misfire for <1km), or something AFTER the engine, because the engine does seem to sound okay?

[JBT]

Change the fuel filter if it's overdue. If still no joy, you're down to electrical/ignition gremilns.

[philz]

Next time it does it try pouring a small amount of water over the coil packs
If it runs fine then you need new coils

Well I tried this today, cold fridge water, didn't help.

And the reason I did this was thinking it was warm engine bay, because it's quite hot today.

So now:

I turned it on this morning, 9am, nice and cool, car ran fine.

Turned the car on at 11am, weather getting quite warm, and hot, the car is misfiring.

So if we revert back:
On Wednesday morning, when I had left the car overnight, the car ran good.
Later in the day, it started to misfire again.
New plugs in the afternoon, ran good, no misfire.
Later it misfired.

Thursday morning, start it up, still good.
Later in the day misfire.

Friday did not turn the car on in the morning.
New leads in the afternoon, still haven't touched the car yet until I put in the new leads and try it again... the car is misfiring.
I notice that the engine doesn't shake as much as before, with the new leads and plugs.

JBT: I've also got a new fuel filter, so I'll see how that goes.