Strange idle

[Guest]

A few months back I cleaned the throttle body because of a code when checking with VagCom. Since then, more noticeable now it's cold, I have a slightly erratic idle. Not all the time but occasionaly, starting a warm/hot engine it will idle around the grand mark briefly then settle down. Temp gauge sits just above half the norm in this weather too. Suspect temp sender?

[mac11irl]

When you say ereatic idle, do you mean its bouncing around a bit?if so Unplug the maf. 

If it runs the same, its knackered, get a genuine replacement as the vw engines dont like aftermarket ones.

 

If you mean your cold idle is sitting a bit higher than "summer" and the temp gauge isnt showing higher than 70° (ish) then its most likely the CTS.

[Guest]

Hi and thanks for the reply. Wrong choice of word, erratic. I meant more unusual. 

"If you mean your cold idle is sitting a bit higher than "summer" and the temp gauge isn't showing higher than 70°", that sums it up nicely. Will get onto TPS for a new temp sensor.

[Guest]

Just a quick update, new CTS fitted and has made only a small difference to running temp. Now gets up to 80 degrees but still have the warm/hot start puzzle. On starting the engine will race up to 2000 RPM then drop down to idle.

[mac11irl]

Did you get a genuine cts?

When it drops back to idle, is it settling nicely at "normal" idle?

How long is it spending at 2k rpm?

[Guest]

Hi mac. 

Picked up CTS from TPS locally, identical to the one that came out, green top.

When it settles, down to normal RPM, around 700. High RPM lasts a second or so.

[octyal]

Do you touch the throttle when you start the car? ie give it some gas?

[Guest]

Hi octyal, nope.