Misfire problem when cold!

[scootmuldoon]

Hi there,
I have a 2000 'X' reg C70 2.3 T5 auto.
I recently got it serviced about 4 weeks ago including timing belt/tensioner, air filter and pollen filter. The spark plugs were checked and cleaned but not replaced as they looked ok. (had only done about 6000 miles since last replaced).
Since then every time i start it in the morning there is a slight misfire for about 10 seconds, the rev counter fluctuates and if i rev it, it stutters until it clears. It seems a little smokey as if burning petrol but once it clears its fine. After that it runs perfect for the rest of the day.
Any help or suggestions would be great as i dont want to start replacing parts if its not going to solve the problem. Thanks.

[chow]

Originally Posted by scootmuldoon

Hi there,
I have a 2000 'X' reg C70 2.3 T5 auto.
I recently got it serviced about 4 weeks ago including timing belt/tensioner, air filter and pollen filter. The spark plugs were checked and cleaned but not replaced as they looked ok. (had only done about 6000 miles since last replaced).
Since then every time i start it in the morning there is a slight misfire for about 10 seconds, the rev counter fluctuates and if i rev it, it stutters until it clears. It seems a little smokey as if burning petrol but once it clears its fine. After that it runs perfect for the rest of the day.
Any help or suggestions would be great as i dont want to start replacing parts if its not going to solve the problem. Thanks.

if the problem started when you had the work done i would get it back sharpish and ask them to check it out

[capt jack]

I agree with chow.

Something ain't been put back properly.

Would suspect air filter box, air inlet ducting, plugs, plug lead.

Servicing is supposed to make it run better - not worse!

Jack

[scootmuldoon]

Hello again,

Just had my car checked over by the garage who carried out the service and they cant find whats wrong with it! They said it could be an injector problem or maybe fuel pump/filter etc but not sure.

Any help would be most welcome as i dont want to start shelling out money for stuff it doesnt need.

Thanks.

[scootmuldoon]

Update folks - today i got my car back after being checked out by another garage. Have now been told that the plugs need changed, my throttle body is sticking and needs either cleaned or replaced but is a bit of a job to do and my mass air meter needs replacing. Is there anyway of checking/doing this myself and do you think that by replacing these parts it would fix the problem?

Thanks.

[glock19]

You should have gone back to the first shop the day after you had the cold start problem. After a month, I doubt if they'll re-check the car again for free.

Anyway, if it's Air Mass, then a code reader should point it out. Plugs usually shows end-of-life signs under load or high speeds. Throttle sticking happens irrespective of hot/cold. I figure there's a loose vacuum hose (black smoke) somewhere or maybe the idle valve (engine hunting) is abit sticky.

BTW, did you mentioned when the car misfired? Parked or on the go ?

[scootmuldoon]

The car only runs rough for about 10/15 seconds first time i start it that morning/day whilst sitting still (parked). After that time it runs perfect under normal driving conditions and whilst under boost etc. I can then leave the car for hours and when i start it again its still fine (only seems to happen when its been left overnight).

Is there anyway of telling whether or not it could be the air mass meter just by looking at it?

Where exactly is the idle control valve and can it be cleaned or would i be better off just getting a new one?

[dmkelly]

This happen with our 2.5 t V70 and it turned out to be a temp sensor by the front bumper. Apparently the ecu was getting confused as to whether the car was up to temp. Changed it problem cured.

Worth a look.

[glock19]

If engine runs rough after along standstill, check your fuel regulator (at fuel rail) to see if petrol is leaking back into the vacuum hose side. Loss of fuel pressure is common in the s/v40 series.

As for the idle valve, it near the throttle body - you might have to remove a plastic cover to see it.

[scootmuldoon]

Another update on my C70.
Took the car to volvo yesterday to checked and they phoned me today telling me that there are 3 fault codes stored being - cylinders 1 2 and 3 are down causing it to misfire when cold. The guy told me that he will replace the plugs and leave it overnight and try starting it again in the morning. Hopefully that will clear it!

Ill let you's know how i get on.