Bonsoir

Problem:

My car has the occasional lumpy idle that some report, nothing really to write home about I suppose, but tonight I noticed a really quite violent idling/shaking whilst waiting at a set of lights. I revved the car and it felt VERY reluctant to rev and didn't sound too happy either - it also took a long time for the revs to fall. Switched off, gave it a couple of secs, turned the key and prayed and it fired and seemed to be OK. I've run VCDS tonight and there is no engine fault code.

Related issues?

I feel like the car is down on power a bit, not much but not quite the wheel spinning monster it had been (when provoked, which is not very often). I had also noticed it had hesitated slightly a couple of times under load in high gear and plugged in VCDS to see if anything was amiss.

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Address 01: Engine Labels: 06F-907-115-AXX.lbl

Part No SW: 1Z0 907 115 A HW: 8P0 907 115 B

Component: 2.0l R4/4V TFSI 0040

Revision: 5BH16--- Serial number: SKZ7Z0F4012513

Coding: 0203000318070160

Shop #: WSC 00191 264 15243

VCID: 336F3044522E491

1 Fault Found:

000135 - Fuel Rail/System Pressure

P0087 - 002 - Too Low - Intermittent

Freeze Frame:

Fault Status: 00100010

Fault Priority: 0

Fault Frequency: 2

Mileage: 103462 km

Time Indication: 0

Date: 2000.00.00

Time: 16:05:42

Freeze Frame:

RPM: 3756 /min

Load: 89.4 %

Speed: 128.0 km/h

Temperature: 90.0°C

Temperature: 22.0°C

Absolute Pres.: 1020.0 mbar

Voltage: 14.224 V

Readiness: 0000 0000

I've since cleared that code and it hasn't come back.

I'd also run some logs (don't have one on this computer) and measured requested fuel rail pressure against actual - one of several logs performed back to back, I had one instance where actual had dropped off from 109.99 to around 60 bar before jumping back up to normal again. A few more logging runs couldn't replicate the problem.

So is it likely to be the pump on the way out or could it be a sensor or the cam follower?

Car is running an Oscarli stage 1 map.

Anything else could that could be the cause?

Cheers

First port of call would be the fuel filter. It's about £15 for the part and takes about 10-15 mins to replace which includes jacking the car up.

Once again car details would help! Pd or cr?

Profile says 07 Octavia VRS TFSI.

Scan shows Component: 2.0I R4/V4 TFSI 0040

HTH.

Hmm what would I do.......

I'd start by checking the follower, then replacing the fuel filter, then the sensor on the HPFP in that order. Lastly the HPFP.

Have you got block 115 logs?

First port of call would be the fuel filter. It's about £15 for the part and takes about 10-15 mins to replace which includes jacking the car up.

Would the filter affect the pressure Carl (assuming the filter gets blocked and stops fuel getting to the rail). Could it happen intermittently?

I have some block 115 logs on my other PC, I'll take a screenshot later and post it up here.

This is my area of concern (in yellow)

Block230log by jonnyguitar, on Flickr

At the point where the rail pressure drops and the car seems to try to be "safe", I notice that boost is also restricted. Is there something properly wrong or is it a function of the car trying to right itself?

First port of call would be the fuel filter. It's about £15 for the part and takes about 10-15 mins to replace which includes jacking the car up.

You jack up the car to change the fuel filter?

Where is it on the TFSI?

I would send Oscarli your logs, you're running a lot of boost pressure there and the pump can't cope by the look of it. My stage 1 was no where near that amount of boost, that's over 1.4bar!

That 1.4+ bar is actual boost, rather than requested (although I agree that's high as well) so it does look like there is a mechanical reason for the car to be overboosting.

You jack up the car to change the fuel filter?

Where is it on the TFSI?

Under the car on the o/s next to the fuel tank.

I've had this that got a bit worse over the last couple of months, quite severe engine judder at higher speeds at lower revs (but still well within the power band).

My car went in for a service last week, which included air filter, oil filter and spark plug change and the juddering has now completely disappeared, car feels much smoother.

Regarding the lumpy idle/loss of power, I'd look to replace the PCV valve first, it's a v.cheap part (£36 from dealer) and a failing PCV valve is well-known for causing those issues.

Info on replacing it here: http://vagdrivers.ne...showtopic=40537

and here: http://www.briskoda....-bkr8eix-plugs/

PCV valve latest part no:

06F 129 101 N

Edit: dealer had no idea what I meant by "PCV", they referred to it as a pressure regulator valve.

Also as your car is mapped it's likely that you'll need to replace your diverter valve with a newer rev D one, which is more robust, *fairly* straight-forward to do if you're handy with a spanner and have access to ramps, new DV will cost £50 from dealer, part no:

06H 145 710 D

Edited 27 June, 201213 yr by chr1staylor

I plan to change the PCV next weekend, birthday this weekend so will be bladdered for two days, i get the lumpy idle too so ordered the PCV and a new set of plugs and a fuel filter.

It pulls perfectly though right up to 6500rpm its really nice.