RobNorwich
15-04-2006, 07:58 PM
Hi everyone, Im new to this site and new to Volkswagen having recently purchsed a 1997 1.8 20v Passat. Until now I have been a "Ford" only guy but having driven my partners passat I am now a VW Convert.
My problem is this:- The car does not idle smoothly, its lumpy and feels like a misfire or as tho the ECU is constantly trying to change or correct something. There is a definite hesitation on acceleration but this seems less pronounced once your past 2000 rpm - if you open the throttle from say 1500 rpm there is a brief spurt of acceration followed by a definite hesitation - then it clears and off it goes right up to red line if you let it. I would emphasise that this is the NON turbo engine. The car also has a rich smell to the exhaust.
Had the codes read today and there was a mention that something within the throttle body was "at the limits of travel". The guy didnt really exlain too well what it was but im assuming its something like the idle speed control side or the throttle position sensor? He said that the throttle body would require removal and cleaning. Once done he said that the ECU would need re programming to set the upper and lower limits for "the parameters" In total this would cost me 80 quid if he did it (2 hrs lab & 30 quid for code read/set). Last night after a run the engine was very reluctant to be revved and felt like it was flooding. There is no feel of misfire when you have gone beyond the RPM where you get hesitation.
My question is does this sound like a dirty throttle body to you? Would it cause hesitation as described? And is cleaning likely to resolve it? Also does the ECU Really need setting or would removing the battery for 30 mins not allow the ecu to re learn the paramters?
To me this feels (and smells) like a failure in the Hego sensor or the TPS - but neither have triggered a fault code. Air Mass has also been mentioned and one guy suggested I disconnected it and drove the car - I did this despite not really wanting to trigger any more codes yet the car stil drove exactly the same - no change.
Sorry for the long posting - im just trying to be as precise as possible. PS Car has full s/h and has plugs and oil in last 4 weeks.
Cheers Rob
My problem is this:- The car does not idle smoothly, its lumpy and feels like a misfire or as tho the ECU is constantly trying to change or correct something. There is a definite hesitation on acceleration but this seems less pronounced once your past 2000 rpm - if you open the throttle from say 1500 rpm there is a brief spurt of acceration followed by a definite hesitation - then it clears and off it goes right up to red line if you let it. I would emphasise that this is the NON turbo engine. The car also has a rich smell to the exhaust.
Had the codes read today and there was a mention that something within the throttle body was "at the limits of travel". The guy didnt really exlain too well what it was but im assuming its something like the idle speed control side or the throttle position sensor? He said that the throttle body would require removal and cleaning. Once done he said that the ECU would need re programming to set the upper and lower limits for "the parameters" In total this would cost me 80 quid if he did it (2 hrs lab & 30 quid for code read/set). Last night after a run the engine was very reluctant to be revved and felt like it was flooding. There is no feel of misfire when you have gone beyond the RPM where you get hesitation.
My question is does this sound like a dirty throttle body to you? Would it cause hesitation as described? And is cleaning likely to resolve it? Also does the ECU Really need setting or would removing the battery for 30 mins not allow the ecu to re learn the paramters?
To me this feels (and smells) like a failure in the Hego sensor or the TPS - but neither have triggered a fault code. Air Mass has also been mentioned and one guy suggested I disconnected it and drove the car - I did this despite not really wanting to trigger any more codes yet the car stil drove exactly the same - no change.
Sorry for the long posting - im just trying to be as precise as possible. PS Car has full s/h and has plugs and oil in last 4 weeks.
Cheers Rob