Strange idle from cold start

[Fozly]

Hey!

I'm new here, been lurking and using the search function for the last month, and I have found everything very useful and informative!

Recently purchased a mk1 2001 leon TDI SE 110, with the ASV engine.

However I have a small issue, sorry if this has been covered but i can't find a problem on here the same as this;


When I start the car in the morning from cold it wont idle properly, for the first few minutes it revs up and down between 800-900rpm (purr purr purr etc.) It sound as if its compensating for load like when you turn lights on or AC in some cars.

I believe this not to be the case as i have tried every combination of systems running at start up. If you tweak the pedal a tad it is fine. It is also fine when up to temperature where it idles smoothly at 900rpm.

I wondered if there was some kind of cold start valve or a MAF/EGR problem?

 

[allh2k]

did you fix this?

 

[Seatmann]

did you fix this?

Did you check the date on the post?

 

[allh2k]

Yes it says hes online???!!??

 

[Fozly]

Hi, yea have been online, never need to post though I'm pro with the search function!!!


Anyway, never fixed the issue, sometimes it happens sometimes it doesn't.

I thought it could be air in the system so bled air out + changed filter, to no avail.

As it happens so uniformly I'm certain it is a sensor/computer/electrical fault.

It only happens for a few moments at start up if left alone. Never stopped it running in -12 degrees winter temperatures so I learn't to live with it.

Any suggestions welcome

 

[Seatmann]

Sounds like it could be a faulty coolant temp sensor or the signal, need to check the real temp with something like vagcom as the gauge is a bit inaccurate.

 

[allh2k]

I will let you know how i get on

 

[asthpsw]

I had exactly the same problem on my Toledo 110BHP......It was the Temp sensor like Seatmann says

Paul