Mysterious acceleration

[VinceOne]

Hi, Fellow Skoders!

 

I have a 2008 Skoda Fabia 2 Estate 1.4. I love this car. However, I took it back to the garage I bought it from in April to find out why it seemed to be "running away" from me acceleration wise. There have been times when I have been driving through the town, on the motorway (especially), on an A road, and it has been going under it's own steam without any acceleration on the pedal - and has been doing from 20-40 miles per hour!  This has proved to be a great mystery, as I can't find any reason for it. This has often happened when going uphill! E. g., coming out of Dumfries over the bridge onto Glasgow Street The garage man tried to explain to me that it had nothing to do with the petrol flow, or acceleration, but was caused by speed momentum built up by the gear ratios, or other gear influences. But, it literally shoots or leaps forward at such times! Although I could understand what he was saying, I am still sceptical, as it seems rather unbelievable to me that a car can do this while not using the accelerator pedal. Also, when this has happened, I have had my foot off the accelerator pedal for quite a long distance, and quite long stretches of road. If this is a typical trait of more modern cars, then I suppose it might be the case, but I am used to taking my foot off the pedal and finding that it decelerates, not accelerates! In addition to this, I used to be a bus driver in the 70s to 80s, and I never experienced anything like this in any vehicle before or since. If it was happening because my pedal was rather close to the brake pedal, and/or my shoe was rather wide, then I could understand that - except that my foot is not on the pedal.  The garage man put some fuel cleaner through the system as a precaution, but that didn't make any difference, and I don't seem to be using more fuel on the long runs; in fact, I have deduced that I am getting 48-55 miles per gallon on motorway runs. (Obviously, in the town the mpg is much less.) Can anyone explain what might be happening here?

 

Kind Regards,

 

Vinchenzo.

[Guest]

Hi Vince, welcome to the site.

 

It sounds as if you have one of two issues. Firstly, you may have a faulty accelerator pedal. These cars are drive by wire, there is not accelerator cable linking it to the engine. The accelerator pedal is an electronic unit and sometimes goes faulty (rarely). The only way to cure that one is to replace the pedal unit. These cost about £55. Secondly, it may just be that you need to reset the throttle position sensor. Speak to your garage about that. I'd try resetting before replacing the pedal. By the way, the garage can test the resistance on the pedal and should be able to confirm the unit is good or bad. Keep us all posted if you will. Good luck!

[Ootohere]

^^^ Very sound advice.

 

Welcome to the forum.

Please do not put off having the fault repaired as it obviously can be dangerous for you and others.

Also since you know about it and have already taken action your insurance underwriter would be concerned if some accident occurs.

 

Was the person that looked at it for you a Skoda / VW Technician or an independent specialist, 

because its rather sad that they left you no better off and i assume with less money in your pocket.

[KenONeill]

Change your kitten garage; the guy who told you that is a dangerous idiot.

 

As per #2, this is almost certainly a fault with the throttle position sensor.

[bignorm]

Sounds like you might be going to slow for the gear your in and the car is trying not to stall.

Read on here before that it's like an anti stall type thing

Edited 15 September, 2016 by bignorm

[Phil-E]

What gear are you in and what are the engine revs when letting go of the throttle?

[KenONeill]

Sounds like you might be going to slow for the gear your in and the car is trying not to stall.

Read on here before that it's like an anti stall type thing

Anti-stall is only supposed to work when the engine can "just about" keep the car moving; it should not make the car accelerate!