misfiring.

[Gingerbread Man]

I've a misfire. It's a Rover VVC 1.8 petrol engine.

Today I replaced the spark plugs. I've also removed the leads one by one and there doesn't appear to be a duff lead.

I've done some googling and I believe that it could be an injector issue also. I've recently replaced about 10" of of fuel pipe, but didn't knowingly get any crud introduced into the system.

Are injectors easy to test and can they be cleaned? Am I right that they could be an issue, or shall I try another route first?

[stevieturbo]

Gingerbread Man said:

I've a misfire. It's a Rover VVC 1.8 petrol engine.

Today I replaced the spark plugs. I've also removed the leads one by one and there doesn't appear to be a duff lead.

I've done some googling and I believe that it could be an injector issue also. I've recently replaced about 10" of of fuel pipe, but didn't knowingly get any crud introduced into the system.

Are injectors easy to test and can they be cleaned? Am I right that they could be an issue, or shall I try another route first?

Well which cylinder has the problem ?

[Gingerbread Man]

I don't know. I was hoping removing the leads might tell me, but I guess as it didn't, the leads are fine.

But then I still don't know what cylinders amiss.

All plugs came out dry and brownish in colour. No odd one out basically.

[DVandrews]

Try removing each injector plug in turn, whichever has no effect will be the duff cylinder, you can then move leads/plugs and or injectors around to see if the fault follows the moved components. I would also consider a compression test to make sure the engine is mechanically sound.

Dave

[stevieturbo]

DVandrews said:

Try removing each injector plug in turn, whichever has no effect will be the duff cylinder, you can then move leads/plugs and or injectors around to see if the fault follows the moved components. I would also consider a compression test to make sure the engine is mechanically sound.

Dave

Agree on the injector, although any rpm change, or lack of change should have been spotted when removing the ignition leads.

Always best to unplug an injector though so you arent chucking even more unburnt fuel into the cat.

Although I guess something more descriptive than "a misfire" might help too.

Is it all the time, hot, cold, at idle, at full load etc etc ?

Is it a misfire on all cylinders, or is the car off a cylinder or two etc etc.

[Gingerbread Man]

It happens straight from start up, so straight from cold. Car idles fine, but sounds a little lumpy, if you blip the throttle, you can hear it fire on (3) cylinders.

[DVandrews]

It's not uncommon for the VVC shaft to move on the drive as they are only a push fit, this can cause the inlet cam timing to alter radically on one cylinder, this will certainly affect the efficiency of that cylinder. I would do a compressin test right away, if the compressions are off then it is worth checking the lift at TDC of each cylinder to see if this has happened, if so catching it now will avoid a very expensive bang up.

Dave

[Gingerbread Man]

Right, here is a sound clip of it running if it helps.

http://www.flickr.com/photos/rednut/8277608366/

[Gingerbread Man]

Went out earlier and wiggled all the connections to make sure that they were all home. Then I started her up, and all sounded well, and went for a drive and it preformed fine. I will keep an eye on it though.

[SebastienClement]

Gingerbread Man said:

Went out earlier and wiggled all the connections to make sure that they were all home. Then I started her up, and all sounded well, and went for a drive and it preformed fine. I will keep an eye on it though.

I would bung a new set of leads on. They're not expensive either. Mine looked fine, however were causing a misfire on number 2.

[Gingerbread Man]

Leads came to my mind, I believe that Magnecor are the call of the day.