1999 Octavia 1.6 SR has problem tickover, due we're told to electronic valve which cost new as much as the value of car . This causes a rise and fall in revs at tickover which must be using excess fuel.

Rather than spend 600€ less labour , id welcome a second hand working replacement . It could be that on this model there are two electronic parts responsible, one in line with air intake and one lower down ? Can this part be taken appart and repaired or cleaned . For example, can carbon deposites cause malfunctioning and subsequently be cleaned off ?

I hope this is the correct forum for this enquiry , sorry if its not .

Portuguy

Does anyone own a similar model Octavia 1.6 SR and had this rising and falling tickover like the engine is ' hunting '? Its in the range of 1200 revs to 1800revs . The plugs are new tripple spark type. Id be very interested if someone had also a lpg gas conversion fitted to compare notes . I notice the date on the four rubber petrol fuel tubes ( to a pump?) mounted on bulkhead are showing their original age 1999 and look dried up with fine cracks but no signs of leakage .

Portuguy

Carbon buildup on the throttle body can cause erratic idle. You can clean it which should help.

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Clean the throttle body with carburator cleaner and check for split hoses arround the engine which can cause vac leak, your symptoms sound to me like vac leak.

Dirty throttle body on our 1.6 16v Leon caused the same problem.

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Thanks Trundlenut and Briskodian , for your valuable opinion . Most welcome . I shall give this part a clean and re- check all hoses . I see which looks like a small vac pump, with casing held closed with a stout U clip. Can i open this to inspect for dirt . ?

I had a similar problem with carbon build up on a Rover 414 which was cured by ceaning up . There the tickover gradually built up revs so the car was cruising without any throttle .Blipping the acelerator sometimes helped to reduce the revs .

On the akl engine which your car has just before the throttle body on the air intake pipe theres a small vac pipe, this pipe just slides on and can work loose. Causing similiar problems to what you describe. Worth a look

Thanks Brownbarge ,

One time i found this tube worked loose . Ill re -check . Im suspicious of the coolant sensor and wonder if i can do a test on it Before buying another?

Cheers Portuguy.

Oh dear ...Another backfire in the air filter intake tubes. last time blew the lid off the airfilter box and flexi tube joint came appart at throttle end.This happened on starting up after a short stop and thats with a new shut off gas valve fitted few days ago.Havent had time to investigate the damage yet due to weather conditions. This second, backfire' , 'boom' sound from under the bonnet is not healthy. The car drives usually ok afterwards .Think its time to shut down the two gas in/ out flow taps underneath back corner of car adjacent to gas guage and just run on petrol??? This gas /lpg Landi system is no longer reliable. The BRC equipment seems a much better LPG system i find on a VW Sharan .

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