General 1.2 misfire / stutter

[IanWard]

Hi all,

Can I check if anyone has had issues with an intermittent misfire / stutter with a 1.2 - hers is a 2009 sport (82k)? My daughter said it was playing up so went out for a drive with her and was a bit of a stutter every 1-2min (momentary misfire) but otherwise is running really well. Turns out the misfire happened almost immediately after putting in £20 of fuel.

I managed to borrow a code reader and it gave two codes:
P0300 - Ignition Failures Recongition
P0304 - Cylinder 4 Ignition Failures

Checked the plug and all looked well (only replaced about 3-4000 miles ago) and made sure the HT lead was firmly seated and still the same.

I was kind of leaning towards potentially bad fuel? told her to run it down and next time dont use supermarket E10, but go premium E5 (shell etc) the misfire has improved massively but still the occasional stutter - maybe once every 10 mins, she's then gone back and put E10 in and back to more frequent issues. up until now appears to have been fine on E10 - but wanted to check others experiences and if anyone else has had issues.

I think I need to borrow the reader again and check if it is still cylinder 4 which at least narrows it down - any ideas?

Many Thanks - Ian

 

[bugsymike]

I have told my daughter to only use the E5 fuel and hers is a 12 plate Punto Evo, modern fuel with 10% ethanol is rubbish for older cars. However on your issue, any chance it is a coil pack going down, if you are happy with the spark plugs.
On a slightly different line one of my sisters had a Honda Jazz always serviced by the dealers from new and had occasional misfires, they supplied her two new expensive coil packs and problem was still there. I am old school and every service would replace the spark plugs for reliability for my customers, I suggested her garage do that for her, even though according to their schedule they were not due, but I got her to insist. Surprise , surprise problem fixed!
I think the reason is with modern high voltage ignition systems the plug electrodes erode away, the gaps get larger so the coil has to supply higher voltage to fire / jump across the gap, this makes the coils more prone to breaking down as the spark takes the easiest route.
The reason I don't like cleaning and regaping plugs is in the old days we had a Champion Spark plug machine which would sandblast and test a plug, I found you could test a brand new plug to the point it started to break down, then clean it and it would break down earlier, also even a little wider gap than recommended would cause earlier breakdown. Also resister plugs and suppressed leads may reduce interference , but they also take higher voltages to fire them so increasing chance of breakdown.

 

[IanWard]

I have told my daughter to only use the E5 fuel and hers is a 12 plate Punto Evo, modern fuel with 10% ethanol is rubbish for older cars. However on your issue, any chance it is a coil pack going down, if you are happy with the spark plugs.
On a slightly different line one of my sisters had a Honda Jazz always serviced by the dealers from new and had occasional misfires, they supplied her two new expensive coil packs and problem was still there. I am old school and every service would replace the spark plugs for reliability for my customers, I suggested her garage do that for her, even though according to their schedule they were not due, but I got her to insist. Surprise , surprise problem fixed!
I think the reason is with modern high voltage ignition systems the plug electrodes erode away, the gaps get larger so the coil has to supply higher voltage to fire / jump across the gap, this makes the coils more prone to breaking down as the spark takes the easiest route.
The reason I don't like cleaning and regaping plugs is in the old days we had a Champion Spark plug machine which would sandblast and test a plug, I found you could test a brand new plug to the point it started to break down, then clean it and it would break down earlier, also even a little wider gap than recommended would cause earlier breakdown. Also resister plugs and suppressed leads may reduce interference , but they also take higher voltages to fire them so increasing chance of breakdown.

Thanks Mike - coil pack is a possibility I guess

 

[bugsymike]

Check plug gaps are correct also.

 

[Farrah]

Ours was a coil pack same symptoms........before spending out on a new one as they can be pricey remove the rubber boot at the end of the coil pack which will expose the inner spring........check the condition of the metal contact to the spring at the end of the coil part and clean it.....one of ours was quite oxydised so cleaned it up and car has been fine since.

Bye

 

[Ralf S.]

I don't think it will be the fuel. For sure E5 is more saucy but a fuel issue would happen more often, and become more apparent under load (accelerating up a slight slope etc.) whereas yours sounds like it just stutters for a split-second at random.

If it's just one cylinder causing the glitch (as it sounds?) then it's more likely to be the HT lead or plug, as above... so look at no.4 and clean up the connectors on the HT lead ends... make sure the spark plug's little screw-on cap is tight and that it all looks well... no arcing, burn marks, frayed or cracked lead insulation etc.

My money is on the coil tough.. The coils used to be the same and without knowing for sure, for your engine, I guess they still are. You can swap the coil positions over and see whether the problem moves to another cylinder. I can't remember how they're wired up.. but c2 and c4 may share one coil, and c1 and c3 will share the other (you'll be able to tell by following the leads from the coils to the spark plugs).


Ralf S.

 

[John202020]

Try the easy/cheap things first, new plugs(were the old ones standard or Iridium?) New plug leads.
Our 09 suffered misfire shortly after we bought it(7 years ago), it was very clearly a faulty no. 4 plug lead you could see and hear it flashing over

 

[Farrah]

Here is a picture of my bad coil pack on the right where the spring seats down to the spark plug end...you can actually see the corrosion rust left from the end of the spring...it is simple to remove the end rubbers to expose this area and as you can see the oxydisation was creating a poor intermittent contact. I cleaned all 4 and also the end of the springs where contact is made with a weak solution of phosphoric acid on the tip of a small paint brush....... alternatively a propriotary rust remover or a tiny wire brush would work........the improvements were seen both in acceleration and fuel consumption......

 

[bugsymike]

Bonus! Thats good.

 

[IanWard]

Try the easy/cheap things first, new plugs(were the old ones standard or Iridium?) New plug leads.
Our 09 suffered misfire shortly after we bought it(7 years ago), it was very clearly a faulty no. 4 plug lead you could see and hear it flashing over

Had new plugs (Standard ones) about 3-4000 miles ago, had it out last weekend and looked ok, still on original HT leads though... having just spoke to her she did say the engine light flashed on and off a bit when it first started so could well be pointing to the coil pack...

 

[John202020]

Had new plugs (Standard ones) about 3-4000 miles ago, had it out last weekend and looked ok, still on original HT leads though... having just spoke to her she did say the engine light flashed on and off a bit when it first started so could well be pointing to the coil pack...

That's exactly what ours did eml flashing given the age and cheap cost new leads maybe worth replacing ?

 

[IanWard]

That's exactly what ours did eml flashing given the age and cheap cost new leads maybe worth replacing ?

Replaced the ignition leads for the sake of £13 is one less thing to be at fault, interestingly hadn't logged any further faults and seemed to drive ok when I picked it up and after, hopefully that issue is now resolved... now to assess the crash damage when she gets home

 

[John202020]

now to assess the crash damage when she gets home

Crash damage?

 

[IanWard]

Crash damage?

pulled out on someone today - apparently 'not too bad, but the head light might need packing up a bit though' I dread to think...

 

[John202020]

Mmm, except it to be more than said, however you can repair any of the headlight fixings either DIY or a repair kit, our car has 3 out of 4 snapped off honestly epoxy and match sticks and all good, our drl light all 3 snapped off destroyed epoxy and aluminium all good if need be ask Typecastboy?
Bumper wing headlight/drl bonnet?