Club G40 Forum

Technical => Engine and Transmission => Topic started by: dannyb.G40 on July 15, 2008, 05:23:32 PM

Title: poor idle
Post by: dannyb.G40 on July 15, 2008, 05:23:32 PM
i know theres plenty about this on previous threads but not much about actual effects.

my batteries only kicking out about 11.5V with all the ancilliaries on at idle, and then only about 12.1V at idle with nothing on. Apparently its sposed to be churnin out around 13.0?

incidently at idle my car barely reaches 900rpm as if it keeps wanting to stall it the revs keep dropping. Will this be a result of the low voltage or something else (the lambda has just been replaced). will the alternator actually need replacing or refurbishing (my mate had his g60 refurbed and seems to be fine) or will it be fine.

(oh yeh the car is also slow to turn over is this also a result of poor voltage)

Any help much appreciated

Danny
Title: Re: poor idle
Post by: PeteG40 on July 15, 2008, 05:28:32 PM
sounds like a poor battery - or most probably a poor alternator... New or refurbed is best bet
Title: Re: Re: poor idle
Post by: supercharged spaniel on July 15, 2008, 05:28:50 PM
i think you have answered your own question really.  new alternator seems to be the next move i'd say and go from there. either way it needs sorting wether you like it or not by the sounds of it!  :D
Title: Re: Re: Re: poor idle
Post by: DKnight on July 15, 2008, 05:33:31 PM
i know of a good alternator for sale, your lucky as they are a shit to find at times!
Title: Re: Re: Re: Re: poor idle
Post by: dannyb.G40 on July 15, 2008, 05:33:32 PM
lol i thought as much, just wanted a bit of info from pro's i shall try and get it done later this week

cheers guys
Title: Re: Re: Re: Re: Re: poor idle
Post by: dannyb.G40 on July 15, 2008, 05:34:27 PM
Dk im interested wherebouts n how much!
Title: Re: Re: Re: Re: Re: Re: poor idle
Post by: dannyb.G40 on July 17, 2008, 07:43:46 PM
bit of an update, had the altenator refurb'd and its pumpin out upwards of 14V now...cashback but havent fixed the idling problem so im gunna tek it to a garage n see wot he has 2 say.

oh and whoever thought putting the altenator below the charger inbetween the antiroll bar and intecooler needs shooting, 'twas a rite fiddly bastard!
Title: Re: Re: Re: Re: Re: Re: Re: poor idle
Post by: grayg40 on July 19, 2008, 08:09:52 AM
your idel control valve might be sticking. take the shaft end of a hammer to get down between the intake manifold and give it a tap to see if that works. It worked on mine, you don't want to have to buy a new one from VW cos its about £450 +Vat or there abouts. Someone told me you can take them to parts and give them a clean and grease and should be ok, but there a cunt to get at and okay if you want to take the risk puting it back together wrong.
Or
Try ajusting the screw on back of throttle body but take note of how much turns you turn it so you can put it back to the same place if it doesn't help.
Title: Re: Re: Re: Re: Re: Re: Re: Re: poor idle
Post by: dannyb.G40 on July 19, 2008, 01:39:38 PM
thanks gray ill definately try the old "tap" method cant hurt giving that a go for free!
Title: Re: poor idle
Post by: vwmk3jon on October 10, 2008, 09:43:00 PM
Mine was doing exactly the same. it would idle fine (probably whilst on choke) and then start to hunt, the revs dropping and rising to the point where it would stall.

Checked the Ohm reading on the Co2 pot and it was miles over the 575Ohm (was at 803!) so adjusted that and tweaked the screw on the back of the throttlebody and it seemed to do the business.

Now ive fixed my exhaust as it was leaking like a bitch from the manifold/downpipe gasket, its gone back to idiling rough again. I'm gonna check the timing as i have a feeling its slightly out!

and btw....How fookin much for a new ISV valve?????? I though inline fuel pumps were bad!
Title: Re: poor idle
Post by: GSBellew on October 12, 2008, 01:45:48 AM
I got a new ISV a year ago, think it was more like €250, but I was told its now obsolete and that was supposedly the last one  ???

I had checked with my Bosch agent who told me they went out of production in 2002.