Random Misfire

RoniN

Hi!
I would like to ask for help. I havae bought my vectra about 2 weeks ago. I wouldnt propably even noticed that problem if I didnt strip out the dashboard becouse of the dead fly behind the glass 😃 . I have noticed that bengine check bulb has been removed :wtf: . Obviously I have put new one in and once I have start the engine up it it should be gone but it did stays on. I think WTF?? Went to my mate and he conected the car to the computer and it did show random misfire. He cleared all errors out of the memory and it was ok for the rest of the day. Next morning unfortunetely problem come back. I have to drive every day to work (arround 30 miles) so I have not much time to play with it. When I am driving the engne check light is on then it start flashing few times and come back to stays on possition and this happening all over again. Car is slightly less powerful (with check engine on), but apart from that is as normal. I did read qite a lot about it on this forum, specialy this:
viewtopic.php?f=3&t=15153&p=1136190&hilit=random+misfire#p1136190
And I am worrying that I will also spent hundreds be4 I will find what couse it. Is there any obvious reasond (in my case) why this could happend?? I think the best option would be for me to pop in to some1 who has the same engine and would like to swap coil pack for example to check if thats make any difference. Becouse this is the most expencive part :cry:
I will be gratefull for any help

vocky

set of genuine plugs (£4 each) first, be gentle tightening them up as they only need 18 ft lb's of torque

then it would be the coil pack to try

RoniN

vocky said:
set of genuine plugs (£4 each) first, be gentle tightening them up as they only need 18 ft lb's of torque

then it would be the coil pack to try

Plugs are changed and now I am looking for second hand coil pack :thumbup:
Thanks

ad172

RonIn

Might be worth checking that the fan is working. Not questioning the authenticity of the previous owner but perhaps by removing the bulb of the ECU, they also disabled the fan as that also runs when the car is in limp mode.

Hope you get the problem sorted soon buddy.

Adam

RoniN

Hi again!
Well, fan does work, when engine is hot as it should. I also suspect oxygen sensor - lambda. Other thing. When I rev the engine I can see black smoke comming out from the exhaust. I am slowly starting looking for another engine 🙁

MikeS

faulty front lambda u will notice slight misfire at low revs then it will clear up

Daz

RoniN_ said:

vocky said:
set of genuine plugs (£4 each) first, be gentle tightening them up as they only need 18 ft lb's of torque

then it would be the coil pack to try

Plugs are changed and now I am looking for second hand coil pack :thumbup:
Thanks

I have a coil pack for sale....

RoniN

MikeS said:
faulty front lambda u will notice slight misfire at low revs then it will clear up

When I reset the ecu "check engine" didnt came up staight away. I was traveling to work approx 15 miles and it was fine. On the way back check engine light came back again. When the light is on and I stop at taffic lights I can feel sometimes like engine shakes a little bit occasiony its not running smothly, but on other side is not too bad.

MikeS

unlikely it is the lambda

it wont run that badly to cause the engine to shake

RoniN

MikeS said:
unlikely it is the lambda

it wont run that badly to cause the engine to shake

Its hard for me to describe it. Maybe shaking is to strong, maybe its like a "tick" from time to time. I dont know how to say that notsure.gif, but its like a little misfire...I think.... But still, there is no simple answer for that problem. Only way is to change one thing after another, till I will find it, or buy second hand engine...
BTW. that is interesting. What do You think??
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https://www.youtube.com/watch?v=OyvdWeyDHf4
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RoniN

Little update in the problem. I went to my friend and he connected computer again. This time was Lambda sensor faulty and random misfire. Question is is the lambda causing misfire, or misfire causing lambda fault?? Also after he cleared all errors in the ecu, check engine didnt come up again. I have been driving all day after and all was ok. Next morning on my way to work, after I have done arround 300 yards check engine came up again. All this happen every time and scenario is the same. Errors cleared out. I can driving all day without the faults. Next day (or after my shift when engine is cold) light come up after short drive. I cant decribe it better than that. notsure.gif

BURT150

That is normal tho as it takes a little while for a fault to show if the problem is something that is on its way out rather than knackered!

As said coil pack or lamba or posibbly faulty wiring to either one.

Not to sure but if the chain is quite old and and possibly slack that might cause the random missfire? dunno.. and poor running.

RoniN

I will change both for new parts and we will see. By the way, my car will have mot next week. Chain is very quiet and I cant even hear it. So I think is ok

BURT150

Thats good then. hopefully that'l solve it.

RoniN

BURT150 said:
Thats good then. hopefully that'l solve it.

Yes, fingers cross 🙂

RoniN

New update!
Coil pack has been replaced by another unit and all errors cleared. After arround 300 meters engine check come up again :thumbdown:. Now I will change oxygen sensor. If not car will go on ebay... Have no more money to spent on it. Price will be arround 600 pounds if someone is intersted