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Model specific boards => Golf mk5 => Topic started by: Panthera on 13 February 2013, 12:24

Title: cold start up idle
Post by: Panthera on 13 February 2013, 12:24

When I start up my GTi (cold start), the revs are higher for about a minute or so, then they drop and then I move off. But  of late the revs drop straight away.  So my question is, why does it do this? Anythis to be concerned about?

Darren

Title: Re: cold start up idle
Post by: Poached on 13 February 2013, 14:31

Quote from: Panthera on 13 February 2013, 12:24

When I start up my GTi (cold start), the revs are higher for about a minute or so, then they drop and then I move off. But  of late the revs drop straight away.  So my question is, why does it do this? Anythis to be concerned about?

Darren

Sounds like Cold start idle to warm up the Cats to reduce emissions.

Title: Re: cold start up idle
Post by: dTEA on 13 February 2013, 17:47

nowt to be worried about unless the revs are nearly 2,000.  Different weather, different storage and cold start means it has to respond so the engine is able to tickover with the right amount of air/fuel ratio surely?  if it remains eratic even when warm then i'd be worrying.

Title: Re: cold start up idle
Post by: Panthera on 14 February 2013, 12:28

Its not erratic at all. 

But I would of thought that, with the temperature being colder that the cars revs on cold start up would be at the higher stat then drop to idle rpm.  When I mean higher revs - 1150rpm (appx.) max and drop to about 750rpm appx.

Sometimes the revs are 800rpm/850rpm then drop to 750rpm (appx.)

Title: Re: cold start up idle
Post by: Rhyso on 14 February 2013, 12:43

What's the temperature been like overnight?  If it's been mild then it won't need to rev so high as all the fluids will be wamish to a degree

If it's been very cold then obviously it will increase the fueling

Title: Re: cold start up idle
Post by: dTEA on 14 February 2013, 14:13

And that will be affected with where its stored. Out on road or driveway or garage? Certainly doesn't seem like much to worry about.

Title: Re: cold start up idle
Post by: Panthera on 15 February 2013, 12:09

Quote from: dTEA on 14 February 2013, 14:13

And that will be affected with where its stored. Out on road or driveway or garage? Certainly doesn't seem like much to worry about.

Thats good.

Title: Re: cold start up idle
Post by: Saint Steve on 18 February 2013, 08:09

Quote from: Panthera on 13 February 2013, 12:24

When I start up my GTi (cold start), the revs are higher for about a minute or so, then they drop and then I move off. But  of late the revs drop straight away.  So my question is, why does it do this? Anythis to be concerned about?

Darren

Sounds like you might have a problem with the MAF sensor. Disconnect it before starting the car. If it idles smoothly, you've found the fault.

Might be dirty, use something like brake cleaner to clean it, if that doesn't cure it, they are just over £100 at the dealer. Worth cleaning it 1st before replacing.

Title: Re: cold start up idle
Post by: Panthera on 28 February 2013, 18:17

Thanks for that Steve. 

Since I posted this thread, *touches wood*  its been fine *touches wood*