Gr Yaris - misfire/stutter

Gr Yaris - misfire/stutter

Author
Discussion

randytusk

Original Poster:

1,898 posts

233 months

Saturday 10th February
quotequote all
Hi folks ,

Wonder if anyone can help?

My GR has developed a misfire/stutter at 4000-4500rpm that occurs only with wide open throttle.
It’s fine on part throttle/closed loop.

Dealership has tried and failed to find any faults and could not log a fault code. Sadly the problem is still there but the dealership won’t action anything without a fault code.


popeyewhite

21,336 posts

127 months

Saturday 10th February
quotequote all
Plugs, injectors, fuel pumps are the normal first ports of call..presuming you've not had it mapped.

randytusk

Original Poster:

1,898 posts

233 months

Saturday 10th February
quotequote all
popeyewhite said:
Plugs, injectors, fuel pumps are the normal first ports of call..presuming you've not had it mapped.
Untouched as far I know - bought it at 8k miles from a dealership.

Just hit 36k last week

Yahonza

2,123 posts

37 months

Saturday 10th February
quotequote all
There was someone (in Australia) on one of the forums who had a similar misfire problem, and went through the mill with their Toyota dealer. From what I can recall it was one of the ignition coil packs failing.

randytusk

Original Poster:

1,898 posts

233 months

Sunday 11th February
quotequote all
Well after given the runaround by the dealership, I’ve hooked up my own foxwell OBD.

No CEL but there are 13 misfires logged - all on cylinder 3.

I’m pretty annoyed that I’ve had to look myself and find the problem they couldn’t locate.

Took me all of 5 minutes.


ChrisW.

6,823 posts

262 months

Sunday 11th February
quotequote all
I don't know if it's the same with T, but I was always advised to replace all once a Porsche coil pack started to break down ...

Parts are often cheaper than the labour to trouble shoot / repair any further issues when coil packs are frequent culprits ...

Simon_GH

397 posts

87 months

Sunday 11th February
quotequote all
randytusk said:
Well after given the runaround by the dealership, I’ve hooked up my own foxwell OBD.

No CEL but there are 13 misfires logged - all on cylinder 3.

I’m pretty annoyed that I’ve had to look myself and find the problem they couldn’t locate.

Took me all of 5 minutes.

I’ve got the same issue on a Focus 1.5 petrol turbo. Plugs have improved it but haven’t completely cured the stutter. Sounds exactly the same as yours and no CEL so I haven’t been to Ford for a diagnostic check.

CoolHands

19,442 posts

202 months

Sunday 11th February
quotequote all
Jst buy a coil pack and change it yourself. Should probably change the plugs too at 36000!

Mr_Dave

140 posts

197 months

Monday 12th February
quotequote all
randytusk said:
Well after given the runaround by the dealership, I’ve hooked up my own foxwell OBD.

No CEL but there are 13 misfires logged - all on cylinder 3.

I’m pretty annoyed that I’ve had to look myself and find the problem they couldn’t locate.

Took me all of 5 minutes.
Pretty poor that they didn't find that. Basic stuff...! Missfire under load at peak boost is pretty much guaranteed to be a weak spark. If its the coil pack, it should be covered under the warranty. Plug, well, like CoolHands said, they could be done at 36k miles (mine has a service plan, so never bothered to check when they're due!) I guess you could swap the coil pack to another cylinder to see if the fault follows it, but that really is the dealers job!

randytusk

Original Poster:

1,898 posts

233 months

Monday 12th February
quotequote all
Thanks for the input.

Dealer has dagree to look at it again now I’ve pointed out the issue is with cylinder 3.

The misfire is quite noticeable given there are only 3 cylinders.

The GRY has two injectors per cylinder- I was wondering if the high pressure direct injector is to blame given the issue only occurs under load/wide open throttle above 4k rpm

popeyewhite

21,336 posts

127 months

Monday 12th February
quotequote all
randytusk said:
I was wondering if the high pressure direct injector is to blame given the issue only occurs under load/wide open throttle above 4k rpm
Very possibly, they get dirty over time.

randytusk

Original Poster:

1,898 posts

233 months

Monday 12th February
quotequote all
Simon_GH said:
randytusk said:
Well after given the runaround by the dealership, I’ve hooked up my own foxwell OBD.

No CEL but there are 13 misfires logged - all on cylinder 3.

I’m pretty annoyed that I’ve had to look myself and find the problem they couldn’t locate.

Took me all of 5 minutes.

I’ve got the same issue on a Focus 1.5 petrol turbo. Plugs have improved it but haven’t completely cured the stutter. Sounds exactly the same as yours and no CEL so I haven’t been to Ford for a diagnostic check.
Don’t leave it too long. The catalytic converter doesn’t hold up well to misfires. Last thing you want is to have to replace that as well…..

ecsrobin

17,823 posts

172 months

Sunday 17th March
quotequote all
Think I might have this. Happened on a drive to Scotland for about 20 minutes then the return trip nothing. Drove it this week and it did it a couple of times. Debating just swapping it as although it will be warranty work the time and effort to drop at a dealer I could just swap it.

bennno

12,716 posts

276 months

Sunday 17th March
quotequote all
randytusk said:
Thanks for the input.

Dealer has dagree to look at it again now I’ve pointed out the issue is with cylinder 3.

The misfire is quite noticeable given there are only 3 cylinders.

The GRY has two injectors per cylinder- I was wondering if the high pressure direct injector is to blame given the issue only occurs under load/wide open throttle above 4k rpm
Put fuel system cleaner additive in along with decent 99 Ron fuel?

As per earlier posts, have spark plug been changed. Prob coil pack.

randytusk

Original Poster:

1,898 posts

233 months

Sunday 17th March
quotequote all
Sorry for not updating the thread.

Misifire was located on cylinder 3 that we traced to a faulty coil pack.

Worthy of note is that the onboard computer does not trigger a CEL or store the misfire status when interrogated with tech stream - We had to have a tech stream laptop hooked up to record live data to register it.

To be fair the dealer changed all 3 coil packs - its now driving much much better.

Heads up to anyone that feels their car is hesitating or not performing as expected - hook up and OBD and check the misfire count. I used a Foxwell NT530.

randytusk

Original Poster:

1,898 posts

233 months

Sunday 17th March
quotequote all
ecsrobin said:
Think I might have this. Happened on a drive to Scotland for about 20 minutes then the return trip nothing. Drove it this week and it did it a couple of times. Debating just swapping it as although it will be warranty work the time and effort to drop at a dealer I could just swap it.
coil pack swap is a 5 min job at the most - it's fairly easy to work on this car.