Blown Accelerator problem, Part II

redtom

Well, the car's been in and out of garage now for nigh on two weeks and, to quote my mechanic last night, "We, ahh, don't actually have a clue what's wrong with it".

To recap, I was sitting at a junction recently, out of gear and feet off pedals and noticed car was revving away on its own. When going from, say, 2nd to 3rd, the car would feel like it's almost slowing down and then the acceleration would suddenly kick in with a jerk. Had it in an Advance Pitstop to no avail, and now after it being in garage I'm at a loss...

Should I bring it to an official Volkswagen maintenance shop, if there is such a thing in the Blackrock area? Its a 96 Polo, 1 litre with 36,000 miles on it - I knew the previous owner so I don't feel he sold me a lemon.

My current mechanic took out a part (thing that sits on top of engine with a flap thing on it that opens and closes, I'm sure all you geniuses know what its called and what it does), and told me to try it over last weekend, so I did but same thing happened. So now its been in with him all week, he's had it hooked up to two diagnostic machines and, well, see above for what he said to me...

Just gettin fed up with it at this stage, not gettin anywhere with it all

Any thoughts welcome...

$Leon$

The "thing" is the throttle body

I'm sure he cleaned it - which sounds like what needed doing.

There are some "basic settings" which need to be carried out on the throttle body after it's been cleaned. Not exactly sure what is actually involved in this .

Kimbot

Reset the ECU after getting the throttle body cleaned I would imagine!! Not too sure though but its worth a try!!

crosstownk

When the throttle body is cleaned the throttle angle needs to be reset. I don't think this is done by 'introducing basic settings'. IIRC, it's has to be 'adapted'. Basically dirt on the throttle body cause the angle of the throttle to change. When it has been cleaned it needs to be reset.

You probably should visit a main dealer at this stage, but personally I wouldn't go to the one in Pottery Road - I've had lots of bad experiences there and have heard even more bad stories. Maybe try Foster Motors - I've heard a few good thing about them, but have never used them myself.

redtom

Well, it seems my mechanic has thrown in the towel and recommended that I bring it a shop over in Fairview who specialise in injection issues, because none of the diagnostic machines he's hooked it up to have pinpointed the problem... I've got it back for the weekend and got it home ok, it was idling ok at junctions, but I did notice some jerks and stutters so the problem isn't gone (maybe that was just my driving tho...)

Thanks for the suggestions, hope Fairview crew can get it sorted...

Mr.Diagnostic

Hi,

How often does the symptom happen?

Is it a case that the mechanic did not see the fault happen or that he did not see it happen long enough to diagnose it?

If the fault is present when testing then it is possible to diagnose it. if not, then it can be quite difficult.
Never mind about the 2 daig machines not being able to pinpoint the fault. It is the man holding the diag machine who finds the fault not the machine. Find a specialist to look at it.

best of luck with it.

redtom

Well, he had it out last night himself and when I spoke with him this morning he said "the problem is still there" so it obviously happened while he was driving it - when I left it in with him last tues, it was acting up pretty bad just as I was pulling into his garage and turned off the engine, so we opened the bonnet, I turned it on again and it started acting up straight away - so I know he's seen it as it's happening

He said that he's had problems getting Polos and Golfs to link up right with his machine in the past - I've never had to go to a garage before so I don't know what to make of that...