Vectra cylinder 2 misfire

zhangj5

Hi,

The exhaust emissions warning light of my vectra 2003 1.8 went on last week, like this.

Went to read the error code found cylinder 2 misfired and changed plugs. The light had been off since then, but found

The rpm is not stable while car is idle, it stays at 600 for a while, then goes up to 900-1000 for one or two second, then drops back. It normalll happens only in the evening, very rare in the morning, strange!

car accelerates very sluggish and chokes.

So the question is should i change the coil pack, if it caused by coil pack, the warning light is off now. If it is not, what else can i check, thanks.

anthony4335

You could swap the HT leads from no.2 with another cylinder.

joujoujou

I'd start from cleaning up airflow sensor, throttle body and idle control valve.

Waterson

Yes as above, the throttle body valve can become clogged or the breather hole blocked with carbon/gunk and start to seize against the motor that actuates it. This results in a struggling idle. Best to remove it, clean it up then have it reset using diagnostic computer. I would imagine that (unless incorrectly gapped plugs have been fitted) the issue is unrelated to the work done on it.

zhangj5

Thanks guys. Just put in some fuel injector cleaner, seems better now, will try to do more this weekend.

zhangj5

i can not find where is the idle control valve on vectra 2003 1.8. Does anyone know where it is? Thanks.

zhangj5

Waterson wrote: »

Yes as above, the throttle body valve can become clogged or the breather hole blocked with carbon/gunk and start to seize against the motor that actuates it. This results in a struggling idle. Best to remove it, clean it up then have it reset using diagnostic computer. I would imagine that (unless incorrectly gapped plugs have been fitted) the issue is unrelated to the work done on it.

What should I use to clean the throttle body valve and air flow sensor? Thanks

joujoujou

Get a can of carburettor cleaner (halfords or any motor factor like shop).

Do not touch any elements inside airflow sensor as they're extremely fragile. Just spray it thoroughly and let it dry.

Bobo78

Dont use carb cleaner to clean air flow meter, use electronic component cleaner to clean air flow meter.

joujoujou

Why?

Bobo78

I was looking on the net about this before when I needed to know about cleaning the MAF sensor.
It turns out that carburetor cleaner is too strong for cleaning sensitive electronic components such as MAF sensors and can result in braking (not literally) the MAF sensor.
They always reccomend to use electronic components cleaner because they are made for sensitive stuff like MAF sensors.

joujoujou

Well, cleaned mine up several times using carburettor cleaner - no problem whatsoever. :P