TFSI hesitation/missfires at high rpm's

[jon-tfsi]

As the title suggests im getting missfires on a Leon TFSI Sport.

Has anyone had this problem or know what it could be?
It only happens at over 5000rpm's and there are no fault codes coming up to point me in the right direction.

Engine mods so far: Custom Code Phase1 remap
Neuspeed P Flo Intake
Forge Twintercooler
Milltek Turbo Back Exhaust
Forge DV
Autotech HPFP

Im sure its not any of the mods that are the problem but when the map is switched off the missfire goes away or at least i cant notice it. Putting the map back on seems to highlight an underlying problem.

I thought it could be fuel cuts so fitted the Autotech HPFP....No improvement.
Also changed the plugs and coil packs...............................Still no improvement!!!

Has anyone got any ideas what this could be? Or had this problem?

Any suggestions would be REALLY appreciated.
Also are there any specialists in the North East that could diagnose this?

 

[Al]

Dan will probably be best to help here. When you are saying about no fault codes, can we assume you have checked it with VAGCOM?

 

[jon-tfsi]

It was checed with VAGCOM a while back and there were no codes. Also did some fuel logs and the rail pressure was dropping as it hesitated so it was concluded as fuel cuts.
I fitted the Autotech fuel pump last week and the problem is still there. I am assuming the drop in fuel pressure was the ECU pulling things back to protect the engine.
I should get it checked with VAGCOM again really but as there were no codes last time i thought it would be a good idea to check on the forum before shelling out £40

 

[Al]

Try logging in VAGCOM using advanced measuring blocks. I did mine last night and was surprised with the results to the point where I need to have a look at my car.

Check channels on group 14 for misfires, 115 for boost and group 20 for ignition angle delay. Also check timing on group 11 and fuelling on channel 230.

 

[jon-tfsi]

Thanks for the advice.
Now to find someone with vagcom in my area. The fuelling was checked on block 230 after some advice from someone on here but im pretty sure nothing else was checked.
Im starting to wonder if its an injector?

 

[jon-tfsi]

How much would it be to buy Vagcom suitable for my car? Im getting to the point where i could do with it.
I struggled to find someone last time and would like to do the checks you recomend

 

[Al]

How far North East are you? I would help you out if you are anywhere close.

 

[DanGB]

As suggested by djhorace, you need to do some VAG-COM logging, measure the misfire counters to see if you are indeed getting any misfires. This will log each cylinder. misfires will only throw a code if it misfires a number of times above a threshold.
Could be as simple as a ignition coil or plug going though.

The misfires should be group 15/16, cyl1-4 in vag-com. maybe worth buying it? Could save you money in the long run so you can diagnoise and repair yourself?
Al you'll need is the Micro-CAN from ross-tech. thats the cheapest CAN-BUS compatible lead they do. Check there website.
Very rare for injectors to go though.

Block 230 is the most relevant for fueling, to compare specified and actual rail pressure.
Very rare for injectors to go.

Im sure with the right logging, this can be diagnosed quite easily.

 

[Al]

As Dan said there, VAGCOM would certainly be worthwhile for you to have with the list of mods you have there mate.

 

[jon-tfsi]

How far North East are you? I would help you out if you are anywhere close.

Thanks for the offer djhorace!! I think its quite a trek from mine to yours though. Im in Guisborough near Middlesbrough. Very kind offer though.

 

[jon-tfsi]

As suggested by djhorace, you need to do some VAG-COM logging

The misfires should be group 15/16, cyl1-4 in vag-com. maybe worth buying it? Could save you money in the long run so you can diagnoise and repair yourself?
Al you'll need is the Micro-CAN from ross-tech. thats the cheapest CAN-BUS compatible lead they do. Check there website.

Im sure with the right logging, this can be diagnosed quite easily.

Have had a nosy on their Website Dan.
Is that right this Cable /Dongle doesnt need software to go with it? Im not too flash with computers is it easy enough to use?
Ideally instead of buying Vagcom i ould go to a local garage and get it diagnosed, but the last time i did that i had to explain about looking for fuelling pressures on block 230 and when i mentioned they would be over 110bar they tried to tell me i was daft until they realised and backed down.
It might be time to bite the bullet and buy it myself.

 

[DanGB]

Buy it mate, youve got all the help you need right here.

You purchase the cable, and download the software from there website. the cable contains the 'license key' that allows you to run the latest software.

 

[robdf2]

As a piggy back to this thread , when logging is there a specific gear or speed , revs that need to be achieved , or do we just go for a quick blast down a dual carriageway in the twilight hours?.

Rob.

 

[ares]

That's a common. I would suggest you drop the twintercooler. I am 99% sure you won't see any missfires after that.

 

[jon-tfsi]

Great!!!!! there is a guy local to me who is willing to do some checks using Vagcom.
Is there any other things to check that could be causing this whilst i got the chance?

Changed the plugs
Changed the coil packs
Problem started when map applied(before any other mods)
Problem goes when map is off

I will be buying Vagcom in the future when i have more spare cash but for now i will have to rely on other people (thanks Ryan if your on here)

 

[DanGB]

As a piggy back to this thread , when logging is there a specific gear or speed , revs that need to be achieved , or do we just go for a quick blast down a dual carriageway in the twilight hours?.

Rob.

3rd or 4th gear (4th prefered) until fuel shutoff (limiter).

 

[singh123]

Hi i'm experiencing similar problems, its only when in high gears 4th and above the revs just hang at about 4k, i spoke to a a few tuners they sugessted that it might be my clutch slipping,, are these sympotoms of clutch slipping?

But i have got it booked in for a Vag Com diagnostics @ Awsome GTI

 

[leviathan18]

fuel filter

fuel pump the low pressure one

cam lobe

 

[CupraSport]

sounds like it could be the fueling issue

 

[jamfool]

I finally had a similar issue solved after months of changing components one at a time to rule things out and here's how it played:

Initially the misfire began not long after having the AC pump replaced when it decided to seize up and explode - however it soon became apparent that this had nothing to do with it. We thought it could have been a loose pipe or something nudged during the AC replacement, but no, after an hour inspection there was nothing loose at all.

The misfire firstly seemed to be either after the car had been running for an hour or so under normal low power driving - or it'd be there straight from the off regardless of temperature/fuel type/air conditions etc.

It then began to be almost predictable - drive it with no power applied, changing below 3k revs and it would be fine for a 30mins / 1hr but as soon as you stop at and traffic or pull away applying power on even the slightest of hills and it was there.

Finally this occurred with an engine check light flash and then a permanent engine check light. This resulted in it firing on three cylinders and could barely even drive it the last mile home without pulling over, ignition off and starting up again. Fortunately the dealership had seen another TFSI with no mods experience exactly the same issue which helped to rule the re-map out.

Over 5 months this is what was changed:

1) One coil pack changed on the effected cylinder - misfire still present after this.

2) All spark plugs upgraded - misfire still present

3) All coil packs changed - misfire still present

4) Injector 4 replaced (all seals etc too) - misfire gone and driving better than ever.

The CAM and CAM Follower issue hasn't appeared in my car at all, an '06 model TFSI with 30k and a remap for the last 20k of those.

I must have read 1,000s of posts and threads dedicated to this misfiring issue across the VAG group with the 2.0 TFSI engine, spoke to three different tuning houses using three different remap brands and had the suggestion of upgrading the fuel pump numerous times from different tuners. DanGB provided advice which was well appreciated to help rule things out.

Based on my experience alone there are different components that may fire up similar fault codes although that doesn't necessarily mean that the "normal" component that fails with be the culprit.

There's been wiring looms changed, multiple coil pack changes, fuel pump changes, CAM Follower replacement, fuel pump upgrades etc...and even still there are cars with all those changes that may bring a misfire to the table. After reading so much over the last few months one thing applies regardless - ignition should be as simple as: Fuel Pump, Injectors, Coil Pack, Spark Plug and anything else your TFSI wishes to throw out of its pram!

Besides my absurd rant - i also have CC Phase 1 and i'd bet my badger it isn't caused by the map directly but because under mapped conditions the engine is being asked to do more which is why it's more apparent. If you've had a twintercooler since your map maybe it needs to be tweaked to take advantage of the significantly lowered charge temps?