Cold runing problems.

[CUPRAMUNKY]

Hi all,

After a bit of advice really to see if anybody else has had any problems like this in the past and what they did to put it right.

I have recently brought the Mrs a leon cupra 52 plate auq engine, Lovely car cant fault it apart from this weird splutter in a morning which i didn't notice when I originally looked at it.

Basically if you go to the car when cold and start it up it will tickover spot on however if i go to reverse it off the drive the revs start to go up and down, Not a miss fire more of a small surge between 500 and 1000 rpm. But if you put your foot on the throttle hold it at 1200rpm for about 10 secs it wont do it. I have had it plugged into a Bosch KTS which didn't bring up any fault codes for the car.

I have had a look to see what common stuff we sell at work thinkin either MAF or Temp sender.

Personally havin spoken to a few contacts I am thinkin MAF!

What you reckon!


Secondly where can I buy VAGCOM from with the leads. Are the ones off ebay full versions ???

Where did you guy's get it from??

Any advice would be great.

 

[LEE69]

Temp sender gets my vote.

Ebay is the cable and the freeware version only.


http://www.ross-tech.com/distributors.html

 

[wurzel]

I had exactly this fault over two years ago; eventually the management light came on and one of the Lambda sensors got replaced - problem went away. Somewhere under the car is a connection box that can collect water - worth checking its not just a connection issue (not sure where the box is located but follow the lambda sensor wires)

 

[Steely]

Start the car, let it run with out touching the throttle and let it run off choke (usually takes 50-60 secs) you'll notive that it wont miss after the chokes run off if you blip it,

Do the same the next morning but blip the throttle just after you've started it, see if it starts to miss at all? If it does:

Mine turned out to be a combination of Spark plugs and air filter and a a bit of a clearout down a few country lanes nd use a good quality fuel,

 

[traumapat]

Throttle bodies can be full of muck and sticky when cold often giving similar symptoms.

 

[CUPRAMUNKY]

Thanks for the advice guy's it didn't miss a beat this morning although have noticed a funny smell (think its fuel though) no EML light or faults think it's gonna be a case of waiting for the gremlin to show itself!!!

Keep the ideas coming. I have read a few threads on here and a lot of people say to clear out the throttle housing is this worth doing as a matter of course can it be reset without VAG-COM ??? if so how ?

Or does anyone live local to TELFORD who could do it for me ?? reset it that is?

Thanks

jono

 

[traumapat]

It will need vagcom to reset after cleaning. Have a search on here for TB cleaning

Usually car will idle fine but the moment you use the throttle the revs drop, this improves as it warms up.

Trouble is temp sensors, pipe splits, mafs can give the same symptoms

Interesting the fuel smell. Split breather pipe?

Hope it continues to behave itself

 

[CUPRAMUNKY]

Right me think airmass is the first thing to try as i can borrow one to test and run on the car for a couple of days, if no joy i will try a temp sender assuming same as on the rest of VWG family green 4 pin or black 4 pin both the same green one a newer version.

I think the fuel smell might just be me

Will brake cleaner be ok to clean throttle housing ? i aint gonna try this till last due to it being the only option that will cost me money for re set.

 

[traumapat]

Right me think airmass is the first thing to try as i can borrow one to test and run on the car for a couple of days, if no joy i will try a temp sender assuming same as on the rest of VWG family green 4 pin or black 4 pin both the same green one a newer version.

I think the fuel smell might just be me

Will brake cleaner be ok to clean throttle housing ? i aint gonna try this till last due to it being the only option that will cost me money for re set.

You smell of petrol??

Carb cleaner is ideal.

 

[Wolvotim]

i was getting spluttering from cold so i did a bit of reasearch and a vagcom scan and found my temp sensor had gone changed it yesterday and its sorted now

here's what i did CLICKY

 

[kevh]

Had same problems first thoughts were Maf or TB changed temp sender made no difference, i replaced spark plugs with decent ones replaced air filter cleaned out throttle body (tb) now drives perfect.

 

[CUPRAMUNKY]

I think i have narrowed it down to TB myself. I have taken the intercooler hose off and it has a lot of carbon built up around the butterfly. I didn'nt want to play around with it though until i know i can get a reset done at the same time . Tried MAF already has new air filter when i checked only thing i haven't done is change Temp sender. but the temp gauge is ok and it didnt flag up on a diagnostic computer so i assume it's working ok !

 

[Wolvotim]

i'll reset the TB i have vagcom

 

[kevh]

provided you don't unplug it you shouldn't need to de a reset.

 

[CUPRAMUNKY]

Thanks Tim would be great to arange that.

Kevh i have alway's been told once the butterfly has been moved it will knock it out of sync and cause it to play up ?? I didn't realise that you could clean without disconecting it ??

 

[kevh]

cleaned both sides of TB without touching butterfly the put ignition on put a brick on accelerator this opens butterfly i used a small very soft paint brush to get cleaner in the hard to reach deposit built up places gave another blast with carb cleaner removed brick ignition of the put it all back together. i have seen from other threads people say you can move butterfly by hand but i think thats asking for trouble forcing the stepper motor.

 

[CUPRAMUNKY]

I agree with the forcing chap !! Good way of cleaning it though did it make much difference when you did this ??

 

[kevh]

drove like a different car after cleaning, more responsive better mpg and no hesitation on acceleration. well worth doing and only took about 30 minutes. probably could have done it a bit quicker but i was being careful not to damage anything. i will probably do this as a matter of course on annual services,

 

[LEE69]

provided you don't unplug it you shouldn't need to de a reset.

Read the sticky in this section.

 

[CUPRAMUNKY]

I would have to say that mine hesitates a lot when your going steady, fine though when you ain't hanging round. Now it's clean it will be a lot easier to keep that way i imagine. You wouldn't think it would cause it to be that different but from what everyone say's it's the only thing i can see left on mine that needs attention.


Thanks for the advice guy's!!!