Hi all

As i complained about before, the car hesitates badly under heavy acceleration. Iv been led to believe its the remap itself, this could still be true but boyfriend has mentioned the N75 valve could be causing the problem and after a little research iv found that a few people have had the same problem and have upgraded these valves to J valves or ECS valve.

Anyone done this or had this problem? Iv heard of the N75 many moons ago but dont actually know that much about it, can someone put this in layman terms for me?

The N75 is a boost controller. The J valve and Ecs valve you refer to were used on the mk1 1.8t vRS not mk2.

We do have an N75 on the mk2 but I've not heard of an upgrade.

So if there anything i can do to stop it hesitating?

Have you checked your diverter valve these are known to fail on the tfsi after remap.

Think she's got a diesel.

sorry forgot to mention mines the 2.0tdi pd

Sorry I actually knew that but wasn't thinking!

Have you had the injectors replaced? There seems to be a lot of talk of injector problems on this engine but I know nothing about diesels TBH.

Yeah the injectors have been replaced with the new wiring loom

Full service history, 60k service only been done 3k ago so on paper the car is very healthy

I think it could be anything air or fuel related. Someone just changed a MAF on here to cure a hessitation. You should get some live data looked at before shelling out on what it 'Mite' be.

Its been on vag com about 6 times in a past 2 month, with the last scan only been last week, everything good apparently, thinking a possible boost hose opening or collapsing under load

At what part of the rev range are you experiencing this hesitation?

after been out last night to try and get a positive hesitation from it, it happens all the way through 4th gear when im giving it the beans

I think it could be anything air or fuel related. Someone just changed a MAF on here to cure a hessitation. You should get some live data looked at before shelling out on what it 'Mite' be.

Yeah it was me and I was about to say look at a new MAF.

You can get one for about £60 + VAT + £25 deposit on the exchange. If you've got a screwdriver and a suitably large set of mole grips or hose clamp pliers you'll be able to do it on the spot anyway.

Hmm. I had (still have a bit) a hesitation problem. Mines a 2.0 TDi so a little bit of a different beast but not vastly so.

My hesitation starts when say cruising along at 75/80 in 5th (2.7k- 3k ish rpm) then if I feather the throttle, say there is traffic ahead, then accelerate again there is a hesitation before the engine picks up again and it will go on after that.

Is it similar to your troubles? I've replaced MAF and the coolant sensors to little effect though it does seem a bit smoother overall with this change.

Ill paint the picture!

On a road i use on a daily basis has an uphill duel carriage way in an S bend shape, first corner go round in 3rd to give plently of boost to get up the first part of the hill then put it into forth to carry the speed and as soon as i put it in forth the car will hesitate at first (as soon as the clutch pedel is back up) then it will accelerate then the power will drop off all together then it will come back, drop off again then come back, all the way through the rev range till i put it in 5th. Keeping in mind this is all happening in about 5 seconds so some times the car physically jerks forward and backwards.

OK, here's what I've found on hesitations:

http://uk-mkivs.net/forums/p/30492/259601.aspx#259601

https://sites.google.com/site/1810martin/maf-or-amm-problems

and

http://www.tdiclub.com/TDIFAQ/TDiFAQ-8.html#e

near to the bottom.

Some useful info but make of it what you will. There seems to be no end of little nigglesome issues with all VAG engines across the platforms. Most people probably don't even notice them but people like us do and want it all perfect. I've now given up on perfect and accept very good. Sign of old age I think.

To me it sounds like bouncing boost. The ECU sees the boost rocket up past requested boost so backs it off but because it's seen a good spike it backs it off too much, it boosts hard again to meet the requested boost, the ECU keeps doing this until boost settles down to where it should be.

I had this on my 1.8t with a fairly reputable remap company. I changed lots of parts but it never got better. I then changed remap companies and the problem disappeared. On the new map the boost came in later in the rev range so it didn't spike so early on and create the bouncing effect.

Did this happen before the remap?

To me it sounds like bouncing boost. The ECU sees the boost rocket up past requested boost so backs it off but because it's seen a good spike it backs it off too much, it boosts hard again to meet the requested boost, the ECU keeps doing this until boost settles down to where it should be.

I had this on my 1.8t with a fairly reputable remap company. I changed lots of parts but it never got better. I then changed remap companies and the problem disappeared. On the new map the boost came in later in the rev range so it didn't spike so early on and create the bouncing effect.

Did this happen before the remap?

No this did not happen before the map, i have not ruled out the map been the cause but after i was about the n75 valve i thought it was worth investigating

The company who mapped it have said they will look over the car next week so ill see what he has to say

The MAF is one part of it and the other candidate would be a dirty EGR/Intake system.

I'd certainly get that map looked at though.

Hi,

We have had many customers come to us the PD170 stutter and have fixed all of them!

Please see this thread for more information HERE.

Our remap on the PD170 is £349incVAT.

Thanks.

Rob

Edited 27 February, 201214 yr by Shark_Rob