Is Diagnosing My Low Power Issue A Goer?

[Guest Porker]

It's some time since I posted on this forum but I have owned my TDi Alhambra for over 2 years and despite around 15 visits to 2 Seat main dealers, (including a new engine), I have always had a low power problem.

 

It is intermittent and unfortunately the dealers don't have a clue. They treat me like I'm an idiot when I explain that the MAF has been changed with no difference and are convinced that if they hook it up to their 'computer' enough and replace the MAF often enough it will cure it. Strangely enough it never has. So they change things in the blind hope that things will improve. I've had 3 MAFs, needle lift sensor some other valve on the turbo all to no avail all at a considerable cost. When I say intermittent I do mean every journey. Most mornings I start the engine and get the telltale sluggish throttle response. Turn off then on again and its fine for maybe a couple of miles, then it gets all jittery (like a poor electrical connection) and looses loads of power ie maxed out at 40mph and feels like the throttle only works for the first 25% (not good on the slip road of the M3).

 

Anyway, I have lost total confidence in the main dealer and have shelled out 100's of pounds in the process. So I am wondering whether investing in a VAG lead and software would help diagnose the problem for myself? Is it possible to measure sensor output in real time on this system with my laptop strapped in the passenger seat? Strangely for a Haynes manual they describe the turbo system quite well.

 

I have decided this weekend to check all the pipes for leaks and look at the electrical connectors. Is it worth looking at the ECU as I understand there is a vacuum pipe that runs to this?

[Ivor_E_Tower]

Welcome back, Porker, and sorry to hear that you are still having problems. I take it that you have now used SEAT dealers in Camberley and Farnham? Not sure if there are any VW TDI independents around here; The VW dealer in Guildford is apparently a bit hit-and-miss, and the one in Camberley is expensive (not sure if they are any good). I would have thought that it might be worth your while to trade your Alhambra in against another one, or buy another one with accident damage and start swapping bits over (assuming you have room to store another car off the public highway).

[Guest Porker]

My life would not be worth living if I added yet another car (I have an old Rover 216, a Porsche 911 (currently for sale) and a kit car in the garage!! My wife does not share my interest in cars.

 

The dealer in Farnham has been very good on other matters (he repaired my cat the other day as the outlet pipe had cracked). I think it was actually you that pointed me in their direction. I just don't think they have the specialist knowledge required. As for Camberely I will steer clear permanently. This was where I first went.

 

I probably will end up changing for another. Although I have considered other vehicles I find the configuration really useful for me and will probably stick to one of these derivatives. Not sure whether I will stick with diesel as the fuel consumption is not really an issue as all my fuel is paid for by my employer.

 

An accident damaged one is an idea though as there are a couple of other things that could do with changing.

 

BTW Apologies for the multiple posting, I got a wierd SQL error a couple of times and didn't realise it had posted!!

[Guest j_mchattie]

Im not experienced in this at all, so forgive me if I cock this up.

 

But at a guess, i would start looking at the fuel pump. If its starts sluggishly, and only revs for the first 25% of throttle, AND maxes out at 40mph after running rough - id certainly be looking at the fuel pump/filter/injectors.

 

Sounds like a pretty basic answer, but I might be right!

 

Then again..... Im possibly not.......

[Ivor_E_Tower]

"sluggishness" - drive-by-wire; could be the throttle sensor potentiometer (new accelerator pedal assembly required).

I don't have VAG-COM so do not know if you can take "real-time" readings from the sensors; I would have thought that is was possible though.