Accelerating Pause?

[Guest T120]

Has any one had a problem when accelerating a Tdi manual and it pauses then carries accelerating on as normal.

 

Had this problem earlier today floored the throttle on an overtake and it was like driving an auto when you boot it and then the kick down pauses as its dropping down a gear or two, then carried on accelerating as normal? :o

 

Any info would be much apprecated. :D

[Guest vr6galaxy]

Sounds like your looseing boost! check out all the hoses to the valves and sensors for the fuel and turbo system, I had a similar thing on my last T4 and it was down to a sticking pressure sensor the turbo system! it was only operating at high revs, so it was as you describe like kick down on an auto box occurring!

[Guest T120]

Thanks vr6 it only did it the once this afternoon but I will check out all the relevent pipework over the next couple of days when the mam saab is not using it. :o

[GaryM]

Yes but mainly the other way round, floor it and she takes off then backs off a little.

 

This has been a problem since ownership that I have never got to the bottom of. Things got really bad over time with as I suffered a failing MAF. Effectively the MAF amplified the problem. Floor the throttle and it accelerated well for a few seconds and then it goes real slow. Typically when overtaking. Backing off the throttle and then applying it again gives another boost for a bit.

 

Changed the MAF and the car is much happier but the basic problem is still there, just in the background.

 

I have checked the engine for vaccum leaks and tested turbo vane diaphram with no problems so I'm now thinking that there maybe an electrical fault somewhere (sensor failure).

 

So any thoughts welcome...

[GSMGuy]

Throttle Potentiometer??? Sounds like a bit of VAG-COM is needed...

 

 

Mike

[GaryM]

Thanks GSMGuy I have VAGCOM and nothing is listed as faulty. I do not know enough about it to dig deeper or run tests. I have just got hold of a throttle pedal so I'll give that a go at the weekend.

 

As I say it is such a step change in the acceleration pattern I do feel it could be electrical. If it were a vaccum leak I would expect it to roll off.

[tim-spam]

Hi there,

When accelerating hard in my 2002 Alhambra TDI (especially in the upper 3 gears), the car initially accelerates strongly, then pauses for a very short time, before resuming acceleration at a slightly reduced rate. This tendency is slight, but noticeable, and is possibly just a characteristic of the emission control system coming into play (boost and fueling being reduced slightly to reduce smoke emission?). I guess that the other possibility is very early signs of impending MAF failure. What experiences do others on this forum have?

I must emphasise that the performance is generally very good, especially acceleration between 1500rpm to 2500rpm, and the fuel consumption is around 40 mpg.

Cheers,

Tim