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Model specific boards => Golf mk3 => Topic started by: technics100 on 11 September 2012, 10:08

Title: 16V ABF Cold idle problem
Post by: technics100 on 11 September 2012, 10:08
Hi Folks,

I'm new to Mk3 ownership and picked myself up a 1995 16V Gti a couple of weeks back (135k on it), all was going well until yesterday, I started the car and it wouldn't idle properly.  The revs were hunting and it was going from 600-1500rpm and nearly stalling.  Once warm it was fine.  It did the same thing this morning, after driving 10 miles to work the car is idling spot on around 800

I had a poke about last night, cleaned the TB looked for broken pipes etc, the ISV is buzzing with ignition so it should be working.  while hunting around the net the other thing I thought was the temp sender (one with white plug part number 026 906 161) does that sound like the next logical step?  The car is going really well, revving clean etc.  Also no errors under engine module when checked with one of those wee handheld scanners.  The morning temperature has dropped off the last two mornings, it was 8c today, so don't know whether this has caused the cold start / idle problem


Title: Re: 16V ABF Cold idle problem
Post by: tweed on 11 September 2012, 11:08
Sounds like your on the right step mate!

Most the time it is that part
Title: Re: 16V ABF Cold idle problem
Post by: technics100 on 12 September 2012, 14:00
Changed the sensor last night and it's still doing it, although not as bad.. would it take any time for the engine / ecu to adjust the fuelling etc?  seems to be hunting at higher revs although still dropping to 600rpm the odd time.. once again fine when warmed up..

Anything else to check?
Title: Re: 16V ABF Cold idle problem
Post by: vii-cks on 12 September 2012, 14:06
Coolant temperature sensor on my Golf once was an issue, especially with cold starts.

Is that fairly new? That all ruled out?
Title: Re: 16V ABF Cold idle problem
Post by: technics100 on 12 September 2012, 14:17
Yes, changed it last night.. the wee one with the white top and two pins
Title: Re: 16V ABF Cold idle problem
Post by: tweed on 12 September 2012, 14:18
Coolant temperature sensor on my Golf once was an issue, especially with cold starts.

Is that fairly new? That all ruled out?

Yes replace this with a good quality part and not a cheap copy, as the cheap ones last a month
Title: Re: 16V ABF Cold idle problem
Post by: Screech16v on 12 September 2012, 18:30
Could be an air leak on the intake manifold and as its warms up the leak seals as it expands a bit.
When cold/hunting try spraying brake cleaner at all the intake joints,revs should change if you hit a leak.
Title: Re: 16V ABF Cold idle problem
Post by: tshirt2k on 15 September 2012, 23:46
Change all vacuum lines to 3mm id silicone.
Title: Re: 16V ABF Cold idle problem
Post by: technics100 on 21 September 2012, 13:18
Cheers guys, I was away on holiday so haven't really driven it much. How much 3mm hose would I need to do all vac lines?
Title: Re: 16V ABF Cold idle problem
Post by: tshirt2k on 21 September 2012, 13:54
3m
Title: Re: 16V ABF Cold idle problem
Post by: technics100 on 22 September 2012, 21:28
I got full VCDS today and scanned the car this evening, getting error code

00519 - Intake Manifold Pressure Sensor (G71)
            03-10 - No Signal - Intermittent

Does that indicate the vac line to the ECU?
Title: Re: 16V ABF Cold idle problem
Post by: Screech16v on 23 September 2012, 12:48
As said replace your vac lines especially the one from back of the intake manifold through the scuttle to the ecu,then clear codes.
Title: Re: 16V ABF Cold idle problem
Post by: Metallix on 24 September 2012, 15:43
Open the ECU up,  there is an internal pipe as the sensor is further inwards.   This pipe may be blocked or perished.

(http://vwtech.no-ip.info/images/golf/abfecu2.jpg)

^ see the hose at the bottom of the picture?
Title: Re: 16V ABF Cold idle problem
Post by: technics100 on 24 September 2012, 16:37
I have 3M of pipe ordered, will take the ECU out and have a hoke at it.. Will also try and check with vag-com
Title: Re: 16V ABF Cold idle problem
Post by: technics100 on 29 September 2012, 23:17
Replaced the main vac line to the ECU, also did a few other lines with the 3mm hose.  Also cleaned the throttle body, ISV and adjusted the accelerator cable.. Hasn't done it since.. fingers crossed thats it sorted.. Now to sort that airbox..
Title: Re: 16V ABF Cold idle problem
Post by: Screech16v on 29 September 2012, 23:33
Lets hope thats it  :smiley: