is this normal?

[dan281082]

just accelerated a bit!   when i hit 4th around 3500-4000rpm the revs slightly dropped for a split second then went straight up again like normal acceleration , is this a normal thing for the vrs?

 

need to try replicate it again on way home i think

[YellowCar]

Doesn't sound normal, but it could be a hundred different things, try replicate as you say, look out for other symptoms and let us know.

[dan281082]

i did try on a shorted piece of road and was fine but i nearly ran out of road! . maybe it was cus id not long started the car?

[YellowCar]

Could have just been a bit of crap getting blown through the system, keep your eyes peeled and see what happens.

[dan281082]

fingers crossed, it sounded like over revving from slipping clutch but. the revs dropped not went up.  

[dan281082]

no fault codes on the gizmo tho

[YellowCar]

Ok, looks like you'll be driving in a state of paranoia until it happens again. It's too early to speculate what it could be really. There are some usual suspects but we'll be able to pinpoint it more when more happens I guess. Few things to keep in mind, any brake lights issues? Such as them coming on when brakes not pressed or flickering? Hard to see I know but try and look out for reflections or get someone to check. Any misfires or smell of fuel when it happens? Any boost issues, low boost or surges? Just try and look out for other anomalies, will help us piece it together. Hope that helps.

[IulianE]

no fault codes on the gizmo tho

do you have fuel trimis values?

[dan281082]

no i only have a vs450 scanner. basic stuff.   it happened on way home, no real issues all the way through the gears just a flat spot at 3500-4000 very small tho, i wonder if i should clean throttle body , but ill need to take it to a garage after to get it reset?

[dan281082]

no i only have a vs450 scanner. basic stuff.   it happened on way home, no real issues all the way through the gears just a flat spot at 3500-4000 very small tho, i wonder if i should clean throttle body , but ill need to take it to a garage after to get it reset?

 also only happend in 4th not yet got to those revs in 5th to see if it happens there

[YellowCar]

Never hurts to clean the throttle body if there's residue there. As long as you don't unplug it you won't need to reset. I just unbolted mine, left it plugged in and put a drip tray underneath. Get someone to put ignition on (not engine) and foot on gas to open the flap so you can clean right through. Carb cleaner and a rag is all you need.

As Iulian suggests measuring some blocks would come in handy if you can, would have thought someone on here has vcds in your area. Check the owners map in the diagnostics section.

[IulianE]

I had this problem and I was going insane....because I had a vacuum leak on the turbo tip fuel trim was -12% ,so running very rich,and at 2500rpm it was cutting fuel and the kick was insane....took me 3 months to find it.

[YellowCar]

Sounds like a bit of a nightmare. Dan how is your mpg? Have you had the car long enough to notice any change? What are you getting on a good run?

[dan281082]

only had it a week!  but i managed avg 27mpg other day over a 20 miles run . but around town says about 20mpg. but  its new to me so im a bit heavy footed at the mo!  coming from a 1.6 bora its like a rocket

Edited 15 May, 2015 by dan281082

[YellowCar]

27 mpg sounds a bit low ie rich, even being heavy footed sometimes you can only go as fast as the traffic, so over 20 miles on decent roads? 50mph limits and such, I'd say it's low. I hear you about the novelty factor though.

[dan281082]

yeah 50 miles a hour roads, that was avg tho,   so what would cause a rich running issue?

[kentphil1]

Even when I first had mine in "ooh that goes well" mode, I never dropped under 29mpg, I now average about 35-38mpg now that I'm officially a GOM.

[dan281082]

then i have a issue!

[kentphil1]

Check the simple stuff first, plug gaps, clean throttle body, clean MAF, and as JulianE suggests check for vacuum leaks. The thing is with something like this, you could spend a day doing checks, when 20-30 mins of real time logging on VCDS could save you hours.

[dan281082]

ill clean throttle body tmorrow, then check plugs  and clean maf see how it goes if not could be a trip to vag gargae on pay day for a vag com test

[kentphil1]

Clean the MAF with something like IPA or fuel injector cleaner sprayed into a self sealing sandwich bag about a third full, drop the MAF in and gently shake it about for a few seconds. let it soak for a few more seconds, then take it out and let it air dry. The sensor wire is delicate, try not to fire cleaners at it or you may make it fubar.

 

As to a vag com test, look at the VCDS map on here in the diagnostic section, many of us with VCDS help out members for very liittle - normally beer tokens, will definitely be cheaper than a dealer......................just a thought.

[dan281082]

Small video of my issue . Seems it's over boosting? Only happens when I floor it 4th and 5th.

Also on mpg front I did a run today motorway and town driving avg 33mpg .

Still need to clean throttle body later.

Octavia vrs issue?: https://youtu.be/3fQ0bMD2EBA

[dan281082]

https://youtu.be/WYNdVXbUup4

Better video watch at end as I accelerate again

[YellowCar]

Strangeness, seems to be running smooth even on the drop, I would have thought ignition issue would be more abrupt and misfirey. Might be wrong. Is the car mapped? Plug gap?

Think you need to measure blocks and see what fuel is doing, n75 duty cycle and MAF might also be useful as it's doing it around peak boost or just following.

Mpg is definitely low as we've discussed which could be air leak, or it could be sensor related. Temp sensor does weird things to the running but not sure I've heard it causing anything like this by itself. Could also be a fuelling issue, although a failing pump would often lean out towards top end...unless it's getting confused by something.

As Phil says while you wait to get the data just go through everything you can check for free or low cost. Check pipework, plug condition and gap (0.7 for remap, 0.8 for standard), clean MAF. Once you've cleaned the throttle body, reset it. Leave it plugged in to clean, at least you can still use the car then. Hope you get it sorted.

[dan281082]

Checked hoses no leaks I can see. Will clean everthing later see how it goes one bit at a time