High fuel consumption and pulsing revs when first started

[s-l-i-x]

Hi, i've had my Audi A3 (1.6L 2001) for nearly a year now and the past few months the fuel consumption has risen alot (only get about 120 miles for £20). I should be getting around 180 miles as previously.

Also when you first start the car 50/50 the engine revs pulse up to about 2000 revs up and down for about 10 seconds or so. No fault lights coming on or anything.

Could anyone help please?

[ed'sA3-1.8THK]

you have (3) issues: crank rpm/speed sensor & related components; (2) maf badly aging; (3) time for spark plugs & eng air filter (unless recently changed)

this issue has 4 or more threads discussing in detail

also consider:

also confirm latest revision cold start enrichment water temp sensor (road mileage suddenly suffers when this badly drifts)

maf sensor can be replaced w/o changing complete housing

have you checked for fault codes?

[s-l-i-x]

you have (3) issues: crank rpm/speed sensor & related components; (2) maf badly aging; (3) time for spark plugs & eng air filter (unless recently changed)

this issue has 4 or more threads discussing in detail

also consider:

also confirm latest revision cold start enrichment water temp sensor (road mileage suddenly suffers when this badly drifts)

maf sensor can be replaced w/o changing complete housing

have you checked for fault codes?

To be honest im not too clued up on cars. Thanks for replying. The car had a service about 5 or 6 months ago and had plug etc changed. The car has done 53k miles.

I was going to get it booked into a diagnostic machine, but I was wondering if it would throw up any codes even if there are no warning lights on the dash?

So this should be my next step? Also how much are MAF sensors?

Thank-you

[BVR.Automotive]

Check fault memory.....

Check for any air leaks (fix these first!).....

Clean and adapt the throttle body.....

Take it for a run and then recheck operation and then continue with diagnosis.

They are the two most common and likely problems and will not cost much (if anything) to sort.

Dave