Missfire and no power

[Elviic]

Hi


Car developed a missfire.. Well, the idle is is just not right, stinks from the exhaust and no power at all. This all happened over night.

Unplugged coils one by one and each had a big difference on the running so they seem to be ok. However, the seal is perished on the one closest to the vvt solenoid (which I removed and cleaned as well). So bought a new coil.

I then started removing spark plugs and noticed that it had PFZR6R in.. Read on forums and checked that it requires PFR7Z-TG.

Whilst doing that also noticed that jet wash hose was split and potentially could have leaked on the coils..

Am I correct in thinking that I need new spark plugs? The plugs seem toastey and not wet. Obs, new wash hose too

 

[Frank Perry]

You pretty much answered your own post - you've identified an issue with the washer hose, get that fixed and then replace plugs. The photo of the 2 plugs; I would say they are due for replacement if they are looking like that, they aren't terrible and are likely fine but just for good measure, £49 on a set of new plugs is a worthy spend as it's general maintenance. You can find a set HERE or HERE

I suppose if replacing the coils/spark plugs hasn't resolved your issue, look at your MAP sensor and O2 sensors. I have never had an issue with O2 sensors but I have read that when these tend to go, they cause a rough idle and bad air/fuel ratio - ultimately causing the lack of power and rough idle etc.

Stick with the basics for now and see how you get on, then move onto the more complicated parts next. Hopefully somebody else will have a few other tips and tricks to check out soon..

Good luck and keep us updated!

 

[Foxspeed]

wholeheartedly agree with frank's post!

 

[Elviic]

Right, new spark plugs and still running rough with no power. I had a spare cam sensor and thought to change that one. As I tried to change it, this bloody thing came out!!

Are there different cam sensors?

 

[Elviic]

Just found the part number for it - 8200963886

 

[bedoef]

Do you have any scan tool to check codes?

 

[Elviic]

Do you have any scan tool to check codes?

No codes, my friend. Changed the cam sensor with no luck. Will be taking it to a garage. Perhaps a compression test and see whether fuel injectors working properly.

How do you check the oxygen sensor? I would assume that the possible culprit would be the one on the pre-cat? I did have a new exhaust put on my car (decat) but I still have the pre cat and it was running absolutely fine for months (apart from the usual flat spot).

 

[PITA]

No codes, my friend. Changed the cam sensor with no luck. Will be taking it to a garage. Perhaps a compression test and see whether fuel injectors working properly.

How do you check the oxygen sensor? I would assume that the possible culprit would be the one on the pre-cat? I did have a new exhaust put on my car (decat) but I still have the pre cat and it was running absolutely fine for months (apart from the usual flat spot).

If it’s the lambda sensor then it will be the one in the pre-cat, this one does the fuelling and the second one is to check the cat is doing its job.

 

[bedoef]

If it’s the lambda sensor then it will be the one in the pre-cat, this one does the fuelling and the second one is to check the cat is doing its job.

Yup. Easiest way to check is swap the O2 sensors around. If that solves the issue, then you have a bad sensor, but that would have come up in the error log.

 

[Elviic]

Now then!

Plugged in the car in another reader, which came up with a cam sensor fault - weird as I bought a new cam sensor! Anyway, I cleared the code. However, being a toe rag, I opted for a non genuine cam sensor (due to £££ and did not feel like forking out £60) not sure whether it is the non genuine one that is causing the fault code. I might change the sensors over again to see whether any difference in codes or just order a new one.

I had another play around the coil packs changing them between the cylinders and noticed that one coil would affect the engine much more than the other coils when plugged out. This exact coil would affect all the cylinders (in which ever it would be plugged in). As I had a spare coil, I exchanged it for the spare one and no more misfire!!

Seemed all well, until I drove the car. There is no misfire and the care drives very smooth. However, it seems lower on power. How can I explain it, seems very tame and does not have the bite that it had before. Also, due to having a non resinated de-cat exhaust, I had a flat spot of death which has now completely disappeared. I am just confused, could the cam sensor somehow changed the behaviour of the car i.e. to avoid the flat spot??? Jeez, why these Clios are so temperamental, like a spoilt child.

I will probably order a genuine cam sensor (as the old one had some cracks in the plastic) and see how it goes. I will let you know how it goes. Has anyone else had their flat spots magically disappear when changing sensors?

 

[Elviic]

Fixed!

Misfire was caused by a faulty coil pack.
Loss of power was caused by a non genuine cam sensor.

 

[Frank Perry]

Very happy to hear it's sorted - good work!