missfire problems , running out of ideas .

[keithjames84@gmail.c]

my clio 172 started misfiring on one of the cylinders on monday evening. I went for a short drive to tescos and it was fine . when i came out to drive off the problem started.

Since then I have changed the leads , coil pack, checked each spark plug. they all seem to fire when they are not in the engine.

I managed to get it to fire on 4 cylinders for about 5 mins when i used some damp start before i started buying parts. This is what made me think it was the HT leads playing up. But as i was driving to see how much new HT leads where it just started misfiring again. Seems to be worse under load conditions, or at least that what seemed to set it off again.

I have ordered some new NGK plugs for tomorrow hopefully this will make a difference. But I dont have much hope as I have seen all 4 current plugs create a spark when not inside the cylinder. so there is voltage coming from the coil through the HT lead to the plug.

This is what made me then think it could be the coil pack, if there was a spark but maybe the voltage was to low for it to be a strong spark. But no difference with new coil pack.

Any ideas will be appreciated?

 

[Da]

Could be an O2 sensor issue, I'm having similar problems currently. Does it missfire, hesitate and occasionally cut out?

 

[K-Tec Racing]

take the fuel rail cover off,

with it running

disconnect each injector in turn to see which one makes no difference, thats your problem cylinder

then you need to check the injectors as well to see if they work

IF YOU DO THIS...... UNPLUG THE COILPACK

take out the fuel rail and crank the engine with the injectors pointing somewhere safe, see if they all go?



IF YOU ARE UNSURE ON WHAT OR HOW TO DO THIS.........

DONT DO IT

 

[T.Trophy]

And don't smoke whilst doing it either!!!!

 

[cliosportap]

i think this is ht leads
the second option is o2 sensor
i have a similar issue esspecially low rpms
and use all of this from another car and noting changed
injectors (also test them in bosch and they are ok)
tdc sensor
new plugs
coil pack
clean up o2 sensor with gasoline
also clean all the inlet and throttle
changed fuel filter

at finaly i bought leads form performanceleads.co.uk
i think next week i will recieve them
after that if it will not sortet i will change o2 sensor

 

[keithjames84@gmail.c]

cheers guys for all your feedback so far. I got the new plugs in this morning still same problem. Only thing i did notice when i went to pick up the plugs is that it seems to not misfire when im going down a hill or if i lift off the throttle completely on flat road when coming to traffic lights etc. Other then that its pretty much all the time.

I am 99% sure its cylinder 4 that is not firing properly. I tryed to see if there was fuel being injected with the manifold off, and i think the injector is either not injecting at all or very little on cylinder 4.

Very difficult for me to see as trying to turn it over and look at same time. I stuck the biggest extension bar out of my tool set down the bottom half of the manifold so it could not move and was in front of where the injector is. On cylinder 4 it was pretty much dry on the other cylinders it dripped with fuel.

any ideas where i could get an injector from or is it a case of going to renault??

Cheers for all your help

 

[Aluco]

And don't smoke whilst doing it either!!!!

LOL !



.... boom !



PS. Yes injectors are about £50 from renault for a 1*2 I think* but we had to get one the same day and renault didn't have them in stock so ended up paying £90 at motorfactors.

 

[keithjames84@gmail.c]

cool cheers for advice. I got the fuel rail off and tested the injectors again and its defiantly not working, looks like the plastic connector part has come away from the injector. Phoned around and no one has them in stock. but 58.75+VAT from renault is best I got so went with them. just got to wait till saturday .

Just for the record S.A.S ( shepshed auto spares limited) wanted to charge me 150 quid for 1 injector . Shocking mark up if renault are selling at 58.45+ VAT.

Cheers again for all your help