Car misfiring

Vejovis

I'm hoping there are a few knowledgeable people here, because I don't want to spend a fortune getting a problem diagnosed, only to find out it's easy to fix myself.

I have a 10 year old Astra (petrol), which normally runs fine. However, about 2 months ago I went through a short flooded area (no more than 4 meters across, and lower than the wheel arch in depth) slowly, and everything seemed fine, then about 10 minutes later the car began to do small bunny hops as if it was misfiring. This continued until I needed to slow down and as soon as I took my foot of the accelerator it cut out. Started again immediately though, and all seemed well.

Since then, every time I'm driving in moderate to heavy rain it does exactly the same thing, in light rain or dry weather it's absolutely fine.

Does anyone know what it might be, and how to fix it as cheaply as possible?

[Deleted User]

When my 206 was misfiring it was one of the injectors that needed replacing. It also fixed the random cut-out problem when slowing down too which had been on going for a months before the misfiring started.

Ultrasonic

Deleted_User wrote: »

When my 206 was misfiring it was one of the injectors that needed replacing. It also fixed the random cut-out problem when slowing down too which had been on going for a months before the misfiring started.

Is it likely that driving through water would cause an injector problem, or that one would be aggravated by heavy rain? Sounds unlikely to be me but I'm happy to be corrected.

woody2234

have you tried new spark plugs, that was my problem

Vejovis

No, I have not tried anything yet.

TBH I'm not sure where the spark plugs are, there doesn't seem to be a distributor cap like there used to be.

This is a picture of what it looks like, would they be under the rectangular grey box (above where the yellow cap is)

Strider590

You've got no airbox or air intake, that thing must run and sound as rough as a bag of spanners.....
Water down that hole and it's goodbye engine, in fact just getting dust down there will f**k up your valves.

And have you removed the engine cover? Because that' missing too....

Pretty sure this is what you should be looking at, note the big airbox on the left.

Vejovis

Strider590 wrote: »

You've got no airbox or air intake, that thing must run as rough as a bag of spanners.....
And have you removed the engine cover? Because that' missing too....

That's not my actual engine, just a pic off the net, rather than try and explain the rectangular box I meant.

When it's altogether it looks like this (again not my actual engine, just a pic off the net)

Strider590

Ahh got ya.... Well the plug are down the middle, just above the filler cap.
I'd try WD40 around them to clear out any water, then give it a go.

Do you do long enough journeys to be able to clear or burn off any water that may have entered the exhaust?

Vejovis

Strider590 wrote: »

Ahh got ya.... Well the plug are down the middle, just above the filler cap.
I'd try WD40 around them to clear out any water, then give it a go.

Do you do long enough journeys to be able to clear or burn off any water that may have entered the exhaust?

Most of the time my main journey is in the morning which is 20 mins (about 4 miles), then the same at night. But sometimes I do shorter journeys.

Then occasionally, such as today I'll do a journey of about an hour or so.

[Deleted User]

Ultrasonic wrote: »

Is it likely that driving through water would cause an injector problem, or that one would be aggravated by heavy rain? Sounds unlikely to be me but I'm happy to be corrected.

I don't think my misfiring was to do with driving through water. It was a couple of months back when we had loads of good weather.