Fabia II1.9 TDI erratic idle problem.

From cold my Fabia has recently started to sit at idle anywhere between 1200 down to a minimum of 1000 rpm (above

the normal 900 or so). If it's at 1200rpm say, blipping the throttle may or may not get it to settle at 1000 but no lower. Sometimes

it will go up to 1100 making the car accelerate even with the foot off the pedal. It never sits at the factory 900 any more.

Other than that the engine seems fine with no roughness or loss of power. Fuel consumption is down I would say.

I was made redundant last month so money's very tight - I'm hoping to fix this myself If I can!

Does anybody have any ideas as to what's wrong?

Thanks

Jamie

Jamie, this could be a number of things...but is likely to be, in my opinion something simple such as an air sensor fault on the intake side, and very possibly just a poor connection to one of those sensors. It's possible it's a 'fly by wire' throttle fault but unlikely. I cannot tell you where all the sensors are on the 1.9TDI as I haven't worked on one. But usually there is an air pressure sensor in the airbox and I would take a look at that one first. It usually produces your symptoms exactly if faulty. You may need to leave it at the garage long enough to produce a cold start when they can experience the problem and check for fault codes etc. If it's under warranty it won't cost anything.

Those are just my first thoughts. There are many other things that could cause it, throttle position sensor going faulty, Sticky EGR valve etc, and all simple to correct once the fault code is showing.

Edited 30 April, 201016 yr by Estate Man

Modern tech.. grr

Estate man thank you for your kind reply.

Found the bizzarely easy solution by a good troll of the posts (the search function here perhaps could be improved))

philje123 'I would first try looking towards the throttle body. Sounds to me like it needs re-setting. Disconnect the battery for a good 10 mins. Re-connect and turn the ignition on and leave for 30 seconds. This should let the throttle body "align" itself with the default "idle" position. Then start and see how that works'.

Worked a treat! My last car was a series 2 land rover....is everything now all electronic!!? Basically your were right on the button as to what the problem was..

Again thanks E

Edited 3 May, 201016 yr by bogroll

Bogroll, very glad you found the answer. It's amazing but most cars these days can fix all sorts of problems themselves if you know what to do to start the process! The machines are taking over!!!...

Edited 6 May, 201016 yr by Estate Man