Lacklustre Golf TDI150 Performance

[MikeyB30]

Hi, as a recent purchaser of a Golf TDI 150 I'd appreciate the opinions of you guys who have been driving them for much longer.  Now I 'upgraded' from a Skoda Fabia VRS,which as you know has the 130 TDI engine.
now the performance in this was amazing, always on tap and never a disappointment 
So I figured, a bit of extra oomph, whilst a heavier car, would equal more fun !
Only problem is it feels like it's holding back, you floor it, and whilst I'm not going to get overtaken by a Metro, it feels laboured and inconsistent.
I recently put some diesel redex into it, took it for a drive to Exeter (200 mile journey there and back), and it  perked up for about a week, was much more responsive, but now it's settled back into its 'holding back' mode.
Any ideas, thoughts greatly appreciated as I'm already thinking of changing it for a V6 2.8 version !!

[Rhyso]

I'd put money on it being your MAF.  This regulates the air and fuel mixture and is prone to failing thus creating 'flat spots' witihn the rev range.

Also check for split / loose pipes.

[Ridg]

i've got a TDI 150 too, which i've had for coming upto 4 weeks now i was really pleased when i got mine (although had to change one of the intercooler pipes as that had blown) but then i've come from a 1.4 petrol so its a massive increase for me.

the only think i can say i've noticed so far is that because its got the bigger turbo on it doesn't really kick in untill about 1700 so if you're talking ingear acceleration then there is going to be a little bit of lag unless you change down.

like Rhyso says, take a look at the hoses that connect the turbo to the intercooler and back as thats what went on mine

[MikeyB30]

Thanks for the feedback.  Just had a look around the engine and all of the visible pipes look in good nick and are well seated.
I did notice an oil leak when I looked at the pan at the bottom, and from looking at the service history, an oil leak was noted on the oil return pipe from the turbo, but I can't confirm whether it was done or not.
Could this be a contributing factor ?
I'm just trying to look at the cheap repair options first, as I seem to recall MAFs aren't a cheap option (I had a Seat Leon Cupra once that displayed similarly inconsistent behaviour, but sold it before I got it looked at)

[Organisys]

Money is on the MAF. But do double check all the boost pipes. Other option could be to get your injectors ultrasonically cleaned based on what you said in your first post. Try to find somone with a VAG COM and read any error codes. Does a MAF fault come up on VAGCOM anyone?

[MikeyB30]

It might be worth adding that I fitted a green cotton air filter a couple of weeks after getting it, and it made no difference to the performance at all !.  Whereas in the past on other cars when I've replaced the standard fit one, you do at least notice some improvement

[Rhyso]

ah you have to be careful with what filters you use as some can have an adverse effect on the MAF.  Your new filter could have had a contributing factor I'm afraid 

[RaKeR]

Lose the filter and check out the MAF threads on this forum or on MK1Vs.net.

90% sure it's an air-flow prob.  Had the same with my Bora Sport.  There's a cleaning guide on MK1V and a common swap is for the Merc MAF?  Straight swap for around 30 bucks and a good set of security bits I beleive?  Could be wrong - plus there were people who had bad experiences with it?  But as far as I'm aware it eliminates the common flat spots and allows for a much smother pull?

Anyone else used the Merc Maf?

[MikeyB30]

Thanks again for all the feedback, from looking around the forums some more I'm going to go down the replacement MAF route.  For some reason I had a figure in my head of hundreds to replace, rather than  under £100 for a bosch, which isn't too bad.
One last thing that seems to confirm the MAF issue is my MPG, I can't get better than 45 (overall from a tank) even on a good run, whereas the Skoda never went below 51 no matter how you treated it

[Ridg]

just out of interest how easy is it to change the MAF is it easy to get to etc