Is this a misfire? Does it happen to anyone else?

[Legojon]

So, this is the 5th time this has happened now in 2 weeks.

From a cold start (even though the weather is warm out). I pull away in 1st. No problems. Get to 2nd gear just normal acceleration. Between 2000-3000 revs the car completely loses power. I then get a squeak from the back of the car (I assume the exhaust?) then its away again.

I won't have any troubles then for the rest of the journey. The only trouble is, its caught me out so bad before I've stalled it and nearly had a car go into the back of me.

Could this be DPF related? Build up of soot? I didn't see any smoke or anything though.

 

[Legojon]

Cars been into the garage today. No error codes or leaks... but turns out its the throttle pedal. They reckon cause its a Golf pedal on a Seat, it didn't throw any recognisable error codes, otherwise the dashboard would have lit up.

 

[richicupra]

The pedal has the same part number across the VW range, but hope that's sorted it

 

[Legojon]

Apparently the one I have now is 1K2 721 503 L ... they've ordered 1K2 712 503 AM to replace it. These are both aluminium style, my original pedal is rubber. So I'm kinda worried I'll have the same problem again.

 

[richicupra]

Don't worry about it, they are all the same thing!

 

[Legojon]

Hmm, still no luck. Changed the accelerator pedal from the golf gti back to the original Seat one and had the problem twice.

Things I know:
It happens from a cold start (all day at work or overnight).
It only ever happens once per journey.
Almost always in 2nd gear (may have happened once in 1st)
When it hits 3000 revs, its like I've drove into someone. The car just violently stops.

Things I've tried:
Diagnostics - no error codes
Leak check - nothing
Changed accelerator pedal - same problem
Swapped fuel - interestingly and it may be coincidence the jolt is still there but much less violent.

I'm actually hoping for it to happen more frequently... so at least when I take it in, it does it at the garage. But it didn't happen once in 7 days. Then twice in the last 24 hours.

 

[OldManPooley]

Breaking news, garage diagnoses a problem witch turns out not to fix the fault lol

I know what your saying tho mate. You need a fault to be pretty constant to be able to diagnose it, otherwise its like pissin in the wind.

Cars eh gotta love em.

 

[Legojon]

Grrr... thought I'd update this as I can find few threads with the exact same problem. Four months on and I'm still having the issue. Although it seems to settle for a "jolt". Pulling away in 1st gear earlier this week, accelerate normally, hit 2500k and its like I've just let my foot completely off the accelerator then put it back down. Still no error codes. Changed air filter, no change. Forte seems to help, Millers not.

Got my car booked in Tuesday to remove my map

So driving it stock for a couple of weeks... then a full service (fuel filter, oil change) just to eliminate both. Hopefully if all ok, by the end of October I'll have a Revo map instead and all will be well (except saying goodbye to £400 + likely £250 for the service, but I needed that in November anyway).

If not, dunno what I'm going to do. I've suggested fuel filter, egr, etc... but garage reckon any of them would throw an error code or CEL. So only thing left to try is the map.

 

[s1 evoloution]

do you still get the jolt in power if you try taking the revs over 3.000rpm and above from standing start could be only between 2.500rpm to 3000rpm

 

[Legojon]

do you still get the jolt in power if you try taking the revs over 3.000rpm and above from standing start could be only between 2.500rpm to 3000rpm

Its tricky because its an intermittent fault. At the moment about once every 7-10 days. But of course the engine is cold, so I try not to rev too hard on it from a standstill. All I can say is that if I dip the clutch, just as its about to jolt (by luck more than anything else) then it doesn't jolt and thats it done for a few days.

 

[Legojon]

For some reason, I'm still trying to fix this (rather than just trading the car and moving on).

So I've determined that I get this hesitation around 3000rpm once per day maximum. Happened in summer and winter. From cold start or warm start (if left for a couple of hours+). Regardless of gear seems like its the first time I go past 3000rpm. Like something sticks then lets go and then its fine for the rest of the day. Still no frickin error code!!!

So far tried:
New accelerator pedal
Smoke boost leak test
Air filter
Fuel filter
Removed remap
New intank fuel pump (nothing untoward in tank)
Oil change (worth a try eh!?)
Forte (diesl treatment, dpf, turbo treatment)
Wynns injector cleaner
Archoil AR6400D
Millers Ecoboost

Next on list ... I'm trying to decide between throwing away money on the following:
Walnut blasting intake
New MAF
Injector testing / cleaning
Buying a 2014 Focus ST instead

 

[Darbo]

Have you thought about looking at the turbo? Maybe some gunk settling in there overnight and needing a jolt to get it going again.
I'm only saying this because everything else is already moving, it's only the turbo that comes in when you get through the Rev range.

 

[Legojon]

I did consider that. I read something about giving the turbo a blast to remove soot from the vanes. However, discounted it on the basis that eg I went out Saturday and it was a 70mph dual carriageway / 60mph country road. When getting up to national speed, I hit 5000rpm before I change gear (once engine is warmed fully). I parked the car up for 2 hours (fish n chips mmmmm). Then on leaving, I pulled back onto the 60mph road, knowing the engine was now colder, I was light on the accelerator and changed at 3000-3200. But 2nd gear, 3100rpm ish, massive jolt. Makes no sense.

 

[Darbo]

Only other thing I can suggest is change your gear oil, if the one constant is second gear it might be worth having a look there.

 

[Legojon]

Just checking through my last couple of service sheets... don't think its ever been touched. I'm currently on 38k, any ideas when its supposed to be changed?

 

[Darbo]

I've read in the past that some people have changed it around the 40k mark and the old oil was knackered, but then I've also heard of people finding the old oil OK, someone has a great little walk-through on here somewhere, dead easy job, you can do it on your driveway.

 

[Legojon]

Definately worth giving it a go before I have the injectors removed! Cheers.

 

[Darbo]

Let me know how you get on.

 

[Legojon]

Grrr... pushed for time so got the local garage to do the gearbox oil and thought for a few days it was fixed. But I've come to realise that the problem seems to occur within either the first 1/4 of a tank or last 1/4 of a tank. Garage don't think its the MAF... managed to log when the fault occured. But didn't think to do fuel pressure at the time. So now need to fill up and try n reproduce that random fault again!

Am now looking for a fuel pressure related problem. Already changed the intank fuel pump.

To explain the table... driving in 2nd gear with the accelerator at 40% (Min is 15%, max 85%) on the highlighted bit, the car refuses to rev any higher than 2900 or go faster than 27mph for 3 seconds despite still holding the accelerator. The car itself is jolting back n forward like I'm re-entering orbit. Thats why I suddenly accelerate to 50-60% as I'm thrown forward!!!

 

[Jfox]

Thats is actually very interesting because my mate who has an FTO GPvR has almost the same problem but much higher in the rev range.

He has changed near enough every sensor on his car, injectors, fuel rail, throttle body, plenum etc...

the only thing left is his fuel pressure regulator and fuel pump. So you might be onto something.

the car hits about 6k revs and hesitates a few times then jumps.

GL with fixing it.