Mk5 golf gti tfsi hesitation

[Mackenzie79]

Hi, hoping someone can help. I have a mk5 golf gti tfsi 2.0l. I was told by previous owner that it had stage 1 remap.
The problem I'm having is when I first start up after it has been sat either over night or at work all day. When I go to accelerate it very briefly holds back as though it's getting no fuel.
As I proceed this clears and all is well. I've only had it a couple of weeks and so far bought a new fuel filter, spark plugs and changed the PCV valve. I've been told by my mechanic that the coils look good. Also it is showing no codes and no dash warning lights.

[muff1991]

does it hold back when driving "normally" or when you're giving it some?

[ljc19630]

What revision of DV you running? May well be worth checking and changing to Rev G as a common fault on these cars.


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[Mackenzie79]

I've tried sitting there idling and let the revs drop to 700. If I drive slowly to then end of my road it is fine but surely I shouldn't have to do that. If I put my foot down a little in first and as I'm about to change it does it.
It feels like either the exhaust is blocked or its getting no fuel. It happened this morn so I decided to put my foot down further and it was can only describe as stuttering. I reached the end of my road pulled out and all was fine. Its fast, smooth through all gears. It only does it on start up after its been left standing.
This evening I've cleaned the MAF and changed the temp sensor as advised by my puzzled mechanic. Guess I'll see how it goes in the morning. Have read about the DV valve so will look into it, thanks. Its booked in next week to have live data read so hopefully that will shed some light.

[Mackenzie79]

Just to add, I text the garage I bought it from and described the problem. He said "it's always done it, it's because it's been remapped. It's because the injectors are sorting themselves out as putting more fuel in"
Is this a thing?.. as seems abit odd

[muff1991]

no mate, that's a load of crap.. mapped or not, it shouldn't act up like that! Unless its a bad map! Has the car done this since you brought it?

I asked if it was behaving like this normally or pressing on, as when you first start the car (morning or after work) the car will enter warm up mode (so extra fuel) warm up mode lasts until around 70 degrees ish on the temp gauge. If you're starting the car and driving off trying to give it a little then it will hold back to protect various parts of the engine and turbo etc. once warmed up it will behave correctly.

MAF, Coolant sensor, DV and PCV can usually be the culprit to these types of issues, along with other things. Have you checked the Cam Follower recently? A throttle body clean and alignment wouldn't hurt either.

since your last message, you said about seeing how it goes in the morning.. how did it go? and yes please, let us know how you get on with Live readings assuming its not sorted.

finally: next time you come out to your cold engine (morning or after work) disconnect your Intake Air Temperature sensor and drive off, see what happens. (just disconnect the electrical plug and leave it hanging)

keep us posted mate.

[Mackenzie79]

Hi,
Yes been like it since I bought it. When I first bought it I noticed an oil leak above the temp sensor. I had this fixed and when changing the temp sensor I noticed the connector was full of oil. Maybe this had something to do with it as it has been better since although I haven't floored it from startup and won't.
Never heard of warm up mode but makes sense and comforting to know.  If this is a thing I guess it answers my question. Just always get in and go with previous cars, not had this problem before. Thankyou though much appreciated. I assume you mean don't floor it until its reached 70degrees rather than idling and warming it up that way.